Threat Actors Bypass Gateways with Google Ad Redirects

By Dylan Main and Harsh Patel, Cofense Phishing Defense Center

The Cofense Phishing Defense Center (PDC) has observed a phishing campaign that attempts to steal Office 365 login credentials by luring employees to accept a new Terms of Use and Privacy Policy. This new campaign has been seen across multiple organizations and uses advanced techniques to garner employee login credentials, including a Google Ad Services redirect to fool email gateways.

Figure 1: Headers

The originating IP in the headers of this email proved its source was coming from a legitimate account with the ‘from’ address “info@jtpsecurity[.]co[.]za” It appeared as though this email address was compromised and then used to send the phish to multiple employees. The word “security” in the from address could potentially lull the user into trusting the email’s origin.

Figure 2: Email Preview

At first glance, the user will see “This message was sent with High Importance.” Again, the from address contains the word security and the subject talks about a “Recent Policy Change,” creating urgency to click and handle the matter immediately.

The email body talks about accepting the newly updated “Terms of Use & Privacy Policy.” Also, it notes how this new policy will affect personal data and discontinue all active services on the user’s account. Curious users will likely want to “Learn More.”

Figure 3 shows the URL embedded in both buttons, “Accept” and “Learn More”:

Figure 3: URL redirect of the buttons

As seen in the above figure, the threat actor has utilized a Google Ad Services redirect to pilot users to their phish. This suggests that the threat actor(s) may have paid to have the URL go through an authorized source. In turn, this easily bypasses secure email gateways and exposes employees to the phish.

Upon clicking on either button, users are redirected to a duplicate of the real Microsoft page at the URL:

hXXps://microsoftoffice-servicepolicy-onlineserver[.]comisys[.]host/common/oauth2-authorize

 On this page users are presented with a pop up of the privacy policy the email mentions. In this window there are two notable logos as well, a Microsoft logo and the user’s company’s logo, in a bid to make this page appear that much more legitimate. Scrolling through the text box you can see the Privacy Statement was taken from Microsoft’s website.

Figure 4: First Page of the phishing attack

After accepting the updated policy, the user is then redirected to a Microsoft login page, which impersonates the Office 365 login page. An employee who enters their credentials and clicks “Next” will have sent the Threat Actor(s) their Microsoft credentials and compromised their account.

Figure 5: Second Page (The actual phishing)

Following the login page, users find further reason to believe the update is legitimate, one more box saying, “We’ve updated our terms.” Upon clicking the “Finish” button, they’ll be all set.

Figure 6: Third Page (Post entering credentials)

Last step: users are redirected to the legitimate Microsoft page, their Service Agreement, to complete the scam. Nothing malicious here!

Figure 7: Final Page (Official Microsoft site)

LEARN MORE about the Cofense Phishing Defense Center. See how the PDC’s managed phishing response and remediation stops the phishing attacks that elude email gateways.

Indicators of Compromise:

Network IOCs IP  
hxxps://www[.]googleadservices[.]com/pagead/aclk?sa=L&ai=C3seiJpC5XstooZGJBrPArsADp__a3lyH_4PTjAqoqKfonA8QASC7-_keYISV7IXcHaABzavQ-gPIAQmpAt6UwcHeNU0-qAMByANKqgTEAU_Q2dNvWCQ_LtumFUNLEz16PFVhg8cC3HmYEdlxma4KWUfGkvbdLFpKvCC92odSoiBTw9idw1iHRgreOTD1xyzoBBif4axm3JFTnekl_2_OeuLDQv0U_HzVVt10Iu5SkzsX6nGWyfUgPHIgJkxJqY4me8SG8d0nlmJ8PumQhJhze02bPmqEr4puzh2awPAoHoVPQ7QaXlbeJvf4W7Wexg1RGQ0EqMY8Z7YLfyh6tceagXiYGwWU1r3H9HuiISfj4G-RYYTABM-Sru2hAsAFBfoFBgglEAEYAJAGAaAGLoAHm9SvBYgHAZAHAqgHjs4bqAeT2BuoB7oGqAfw2RuoB_LZG6gHpr4bqAfs1RuoB_PRG6gH7NUbqAeW2BuoB8LaG9gHAMAIAdIIBggAEAIYGoAKAZALA5gLAcgLAYAMAeAS_6jY_crtxomjAdgTDg&ae=1&num=1&cid=CAMSeQClSFh3L5xTIDfFt35D8xjVEHFCYXr5NOlTRany4t_BBsFsAp3b7XCD0nSBKDirzhPVamy0H75uzx6gQxh5_rKDAlBAJWTUCf1Tqi6saFbojDtHd_R8dtCePj4ZvH0zHZWyRITLXvztggY2ibrWY9oLm5X8Wcuetvk&sig=AOD64_0L9hd4oCjDoroDTf6-7Fkon2bwsw&ctype=5&client=ca-pub-1169945711933407&adurl=https%3A%2F%2Fmicrosoftoffice-servicepolicy-onlineserver[.]comisys[.]host172[.]217[.]7[.]226
hxxps://microsoftoffice-servicepolicy-onlineserver[.]comisys[.]host/198[.]23[.]137[.]146
All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.
The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.

Invoice Themed Phishing Emails Are Spreading from Trusted Links

By: Kian Mahdavi, Cofense Phishing Defense Center

The Cofense Phishing Defense Center (PDC) is seeing continued growth in phishing attacks which harvests users’ credentials via genuine file-sharing websites, which are found in environments protected by Proofpoint’s Secure Email Gateway (SEG). A huge factor in this campaign is the confidence users have in emails containing the “trusted” Dropbox reference.

It is tricky for SEGs to keep up with attempts to spread phishing attacks and malware via sharing services such as Dropbox, ShareFile, WeTransfer, Google Docs, Egnyte and even SharePoint. Fortunately, a few of our clients’ users reported the phishing emails via the Cofense Reporter button.

The “traditional” methodology for attackers was to “break in.” Nowadays, they easily can “login,” thanks to sharing sites.

Figure 1 – Body of email showcasing the victory of this attack tying in with user interaction

The spear phishing attack sends a link requesting users to access a purchase order form with a (.pdf) extension. Upon clicking, the attack automatically redirects the user to their default web browser, requesting to click the “Download” button. The website will begin the download inside the “Downloads” folder. Nothing sinister going on, right?

The ‘sent addresses’ TLD – “actionsportsequipment[.]com” – coincidentally relates to the nature of the client’s industry; this demonstrates the extent the attackers went to, in a bid to slip through the “secure” environment. One must question themself: “Was I expecting this transfer?” and “Am I expecting to receive a purchase order from this sender?”

Moreover, since the emails have been authenticated against Dropbox’s internal servers, the emails pass basic email security checks such as DKIM and SPF.

Figure 2 & 3 – Downloadable purchase order file

Once the download has been completed, the user is prompted to open the (.html) link assuming the “purchase order” form would appear, however upon clicking, the campaign redirects the user to a supposed “Microsoft” login page.

In this case, the attackers used the free website builder “Weebly.com” … yet another legitimate source, further deceiving the security measures in place with trusted redirect domains and IPs which will naturally continue to be white-listed and deemed “safe” since millions of users share data with one another on a daily basis.

For this reason, the presence of the padlock appears, adding not only security on both parties, but also the illusion that the website is “secure.”

Figure 5 – Phishing site built by Weebly

Once credentials have been supplied, the campaign redirects the user to the authentic ‘office[.]com’ webpage, which could even be enough to assure users it was a genuine procedure. A user’s personal data could potentially be in the hands of the threat actor, assuming they logged in with their true Microsoft credentials.

Figure 6 – Redirect to Microsoft Office webpage  

Indicators of Compromise:

Network IOCIP
hXXps://www[.]dropbox[.]com/l/AADOPQGXtuDK03QYuvJqI0MbDlDxBTV28Cs
hXXps://www[.]dropbox[.]com/l/AAAtWq-LVZcqXBnFLinUi9rB3LpEijuPo78
162[.]125[.]6[.]1
hXXps://helpsupport0ffice20[.]weebly[.]com/199[.]34[.]228[.]53
199[.]34[.]228[.]54

LEARN MORE about the Cofense Phishing Defense Center. See how the PDC’s managed phishing response and remediation stops the phishing attacks that elude email gateways.

All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.
The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.

HMRC latest target in global COVID relief phishing campaigns

By Jake Longden, Cofense Phishing Defense Center

Taxes and rebates have long been some of a phisher’s favorite targets. Now the coronavirus has provided a fresh new way to exploit this topic: the government grants designed to help small businesses and those out of work due to the pandemic.

The Cofense Phishing Defense Center (PDC) has observed a new phishing campaign in the U.K. that aims to harvest HMRC (Her Majesties Revenue and Customs) credentials and sensitive personal information by preying on employees who are expecting COVID relief grants.

With multiple world governments providing such grants, this is an easily modifiable tactic—simply modify the email to spoof the target country’s tax service.

Figure 1: Email Header

To add authenticity to the email, the threat actors have used an email address (hmrc@hotmail.com) with the impersonated organization in the name and set the name to match (HM Revenue & Customs). That, combined with the subject line, is a great way to attract the user’s interest (“Helping you during this covid from government”). Whilst this sentence is not using the greatest grammar, who wouldn’t want government assistance during these difficult times?

Figure 2: Email Body

When first viewing the email, the user is presented with a notification that the government is offering between £2500 and £7500 in tax grants for those whose work has been affected by the virus. The email includes a link to check their eligibility. With the government publicly and repeatedly mentioning such sums,  the email is believable to inattentive users. The attacker also mentions the “Open Government License v3.0,” a legitimate copyright license used by the Government and Crown Services, to provide additional credibility.

Figure 3: Phishing Page

Once the link is clicked, the user is presented with a realistic clone of the GOV.UK website. This may alleviate concerns a user may have and provide a false sense of security, as the page is extremely similar to the HMRC account sign-in page. The biggest red flag: the URL, just-bee.nl, is not relevant.

Figure 4: Phishing Page

Figure 5: Phishing Page

Here the user is asked to enter some very personal and sensitive data. Another sign that this is a scam: the volume and sensitivity of data requested far exceeds what is required to sign into a legitimate account. The data requested here screams “identity theft/impersonation.”

From there, the user is directed to a page that seems to be loading, to help provide the impression that the data is being processed and an eligibility check performed.

Figure 6: Processing Page

 

Network IOCIP
hXXps://www[.]lagesports[.]com/[.]tmb/xml[.]php69[.]10[.]32[.]186
hXXps://rtoutletpremium[.]com[.]br/[.]well-known/pki-validation/UTR/index[.]php162[.]241[.]182[.]5

 

How Cofense Can Help

Visit Cofense’s Coronavirus Phishing Infocenter to stay up to date as threats evolve. Our site is updated with screenshots and YARA rules as we continue to track campaigns.

All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.
The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.

New Covid-19 Phish Abuses Tax Relief Act to Steal Credentials

By Ashley Atkins, Cofense Phishing Defense Center

For the past few months, the Cofense Phishing Defense Center (PDC) has observed numerous phishing campaigns associated with the coronavirus (COVID-19) pandemic.  These COVID-19-themed phish come in various forms and tend to prey on those fearful of contracting the disease as well as those who are in dire need of economic relief. Recently, the PDC identified a unique version that deserves an overview.

For this attack the user received a malicious email impersonating the US Department of Revenue with the subject: CARES Relief Certificate. The message body references information regarding the 2019 185 Act that has received attention in media outlets and social platforms. Upon researching the Act, it is highly likely the attacker copied that information from a website, made minor changes and created this phishing email, as seen in Figure 1 below.

Figure 1: Email Body

At a glance, this email simply informs users of the tax provisions adopted from the CARES Relief Act and outlines the details regarding it. It also mentions a deadline for applying, and that in order to apply users must fill out an attached secure document. One thing to note, this email arrived a few days after the stated deadline in the email. This may be intentional on the threat actor’s part in order to instill a sense of urgency in users – “you’re late and the deadline has passed!” However, some users may be pressed enough to attempt to apply, thinking it is worth a shot if it could mean receiving relief during this pandemic.

Many obvious red flags are present in this email. Besides the unsightly format, grammatical errors and random property address, the most evident red flag is the sender’s address. The attacker has abused AWeber’s email marketing service. AWeber’s use of SenderID authentication results in the “From” line showing as “Department of Revenue <state=lrs-gov[.]tk[@]send[.]aweber[.]com> on behalf of Department Of Revenue <state[@]lrs-gov[.]tk>”. When reviewing the domain, it seems to read as “Irs” (IRS), but the first letter is actually a lower-case L. The use of the .tk top-level domain (TLD) is worth noting as well. This TLD is the country code for a New Zealand territory called Tokelau. It is also free and one of the top TLDs used in phishing attacks.

Should users go so far as to download and open the “secure” HTML attachment, they are presented with a typically formatted Microsoft login page. This may appear odd, as the threat actor has impersonated a well-known and trusted entity such as the US Department of Revenue.

The fake Microsoft login page prompts for the standard username and password.

Figure 2: Phishing Page

Once credentials are submitted, a PHP script sends the stolen information to the attacker. The HTML’s source code attempts to bypass URL detection by using base tags that splits the malicious URLs into two sections.

Figures 3- 5: Source Code

Network IOCsIP
hxxps://youdiaddy[.]ml/api/api[.]php?192[.]236[.]194[.]247
hxxps://ijodaddy[.]cf/api/api[.]php?23[.]254[.]230[.]115

 

All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.

MFA Bypass Phish Caught: OAuth2 Grants Access to User Data Without a Password

By Elmer Hernandez, Cofense Phishing Defense Center (PDC)

The Cofense Phishing Defense Center (PDC) uncovered a phishing tactic that leverages the OAuth2 framework and OpenID Connect (OIDC) protocol to access user data. The phish is not a typical credential harvester, and even if it was, Multi-Factor Authentication (MFA) wouldn’t have helped. Instead, it attempts to trick users into granting permissions to a rogue application. This is not the first time the tactic has been observed, but it’s a stark reminder that phishing isn’t going to be solved by Multi-Factor Authentication.

Using the lure of a Q1 bonus, the email is crafted to appear to be a normal invite to a SharePoint hosted file. The prospect of receiving an increase to their salary is an effective lure that can lead users to fall prey.

Figure 1 – Email Body

After clicking on the link, users are taken to the legitimate Microsoft Office 365 login page at https://login.microsoftonline.com (Figure 2). However, if one inspects the URL in its entirety, which average users are unlikely to do, a more sinister purpose is revealed.

Figure 2 – O365 Login Page

Anatomy of a URL

First, a quick primer: applications that want to access Office 365 data on behalf of a user do so through Microsoft Graph authorizations. However, they must first obtain an access token from the Microsoft Identity Platform. This is where OAuth2 and OIDC come in. The latter is used to authenticate the user who will be granting the access, and if authentication is successful, the former authorizes (delegates) access for the application. All of this is done without exposing any credentials to the application.

Figure 3 – Entire URL

The response_type parameter denotes the type of access being requested to the Microsoft Identity Platform /authorize endpoint. In this case, both an ID token and an authorization code (id_token+code) are requested. The latter will be exchanged for an access token which will, in turn, be presented by the application to Microsoft Graph for data access.

Next, the redirect uri parameter indicates the location to which authorization responses are sent. This includes tokens and authorization codes. As we can see, responses are sent to hxxps://officehnoc[.]com/office, a domain masquerading as a legitimate Office 365 entity, located at 88[.]80[.]148[.]31 in Sofia, Bulgaria and hosted by BelCloud.

Moving on, the scope parameter shows a list of permissions the user gives to the application (note “%20” represents a blank space). These allow the application to read (read) and/or modify (write) specific resources for the signed in user. If the “All” constraint is present, permissions apply for all such resources in a directory.

For example “contacts.read” enables the application to read only the user’s contacts, whereas “notes.read.all” allows it to read all OneNote notebooks the user has access to, and “Files.ReadWrite.All” to both read and modify (create, update and delete) all files accessible to the user, not only his or her own.

If the attackers were successful, they could grab all the victims’ email and access cloud hosted documents containing sensitive or confidential information. Once the attacker has sensitive information, they can use it to extort victims for a Bitcoin ransom. The same permissions can also be used to download the user’s contact list to be used against fresh victims. Using the address book and old emails would allow the attacker to create hyper-realistic Reply-Chain phishing emails.

Perhaps most concerning however is “offline_access” As access tokens have an expiration time, this permission allows the application to obtain refresh tokens, which can be exchanged for new access tokens. Therefore, users need only to authenticate and approve permissions once to potentially enable indefinite access to their data.

Finally, we find openid and profile which are technically scopes in themselves; openid indicates the application uses OIDC for user authentication, while profile provides basic information such as the user’s name, profile picture, gender and locale among others. This information, known as claims, is sent to the application in the ID token issued by the /authorize endpoint.

After signing in, the user will be asked to confirm one last time that he or she wants to grant the application the aforementioned permissions. If users fail to act, it will be up to domain administrators to spot and deal with any suspicious applications their users might have misguidedly approved.

The OAuth2 phish is a relevant example of adversary adaptation. Not only is there no need to compromise credentials, but touted security measures such as MFA are also bypassed; it is users themselves who unwittingly approve malicious access to their data.

Network IOCIP
hxxps://officehnoc[.]com:8081/office88[.]80[.]148[.]31

 

How Cofense Can Help

Visit Cofense’s Remote Work Phishing Infocenter to stay up to date as threats evolve. Our site is updated with screenshots of real phish that have evaded secure email gateway detection and other helpful resources so you can help keep your organization protected.

All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.
The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.

New Phishing Scam Targets Teleworkers with Bogus Microsoft Teams Notification

By: Kian Mahdavi, Cofense Phishing Defense Center

With the influx of remote workers, it’s a perfect opportunity to flood people’s inboxes with malicious emails and fake links. The Cofense Phishing Defense Center (PDC) recently uncovered a phishing campaign that targets employees to harvest their Microsoft credentials. Ironically, the phish was found in an environment protected by Microsoft’s own secure email gateway (SEG). The phishing email, which was reported to the PDC using the Cofense Reporter button, included a well thought out “AudioChat” notification link supposedly from Microsoft Teams.

Teams is one of the most popular platforms for remote employees. Predictably, the threat actors have taken this into consideration – especially during the COVID-19 pandemic with millions of people teleworking. We expect this trend to continue with similar communication platforms.

Figure 1: Email Body of an official Microsoft Teams example notification

Figure 2: Email Body of illegitimate Microsoft Teams notification

Credit where credit’s due, we were impressed by the effort of the threat actor and their high-quality social engineering tactics. The subject line reads “Chat Message in Teams”- is this just an ordinary notification?

The email content has perfect similarities between Microsoft’s services; in particular, it incorporates matching font size and color as well as the overall layout. The email also includes the generic ‘tips’ section towards the bottom half of the message, evident above in Figure 2. However, there’s a catch: despite the solid efforts of the email content, there are a few tell-tale indications this is a phish. The most obvious sign is the sender’s lengthy spoofed email address:

matcnotification[.]teamadmin_audidsenderderweeu44we7yhw[@]ssiconstructionnw[.]com

The words “notification” and “teamadmin” have been skilfully included within the account name. But more importantly, the TLD – “ssiconstructionwn” – does not contain the all-important ‘Microsoft’ reference. No prize for guessing, it is a construction company located in Seattle, Washington that the attacker has spoofed. Since the TLD is from a legitimate source, not only does it pass basic email security checks, such as DKIM and SPF, but also provides HTTPS displaying the essential green lock to the left of the URL, located below in Figure 3 – a valiant effort on behalf of the threat actor.

On top of that, the text displays: “Teammate sent you an offline message.” Notice the message practices a generic word: “teammate” rather than the specific name of the sender. Contradicting itself, the email includes an initial (JC) of the supposed sender within the avatar, further hindering the legitimacy of the email and raising suspicion.

As mentioned above, the user is requested to click on the “16 second AudioChat,” and once hovered, displays the following link:

hXXps://us19[.]campaign-archive[.]com/?u=0dce22c9638fc90b5c17ea20a&id=6652f42d20

The user’s email address (now redacted) is embedded into the above URL. Companies often use various email protection solutions, and as a result, URLs are often packaged with security phrases. In this phishing campaign, the email contains the words “safelinks.protection” planted at the very beginning of the hover link. This could trip up inquisitive readers who might overlook the rest of the URL and click.

Figure 3: Initial Phishing Page

The phishing page above, where users are forwarded, adheres to Microsoft’s protocol (an almost picture-perfect replica); of course, we are overlooking the forged URL within the web-bar. Once ‘Open Microsoft Teams’ has been clicked, the user should have been automatically redirected to the Microsoft Teams application. Instead, the user is taken on a slight detour to the final link of this phishing attack:

hXXps://imunodar[.]com/wp-content/plugins/wp-picaso/Teams/

Figure 4: Secondary Phishing Page

Once credentials have been supplied, the campaign redirects the user to the authentic ‘office[.]com’ webpage, which could even be enough to assure users it was a genuine procedure. A user’s personal data could potentially be in the hands of the threat actor, assuming they logged in with their true Microsoft credentials.

Indicators of Compromise:

Network IOCIP
hXXps://us19[.]campaign-archive[.]com/?u=0dce22c9638fc90b5c17ea20a&id=6652f42d20
hXXps://imunodar[.]com/wp-content/plugins/wp-picaso/Teams/
104[.]118[.]190[.]227

 

How Cofense Can Help

Visit Cofense’s Remote Work Phishing Infocenter to stay up to date as threats evolve. Our site is updated with screenshots of real phish that have evaded secure email gateway detection and other helpful resources so you can help keep your organization protected.

 
All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.
The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.

A Not So Relieving Tax Relief Email: Threat Actors Take Aim at US Stimulus Efforts

By Ashley Tran, Cofense Phishing Defense Center

The Cofense Phishing Defense Center (PDC) has observed a new phishing campaign that aims to harvest a variety of email credentials specifically from United States citizens.

Countries all around the world are providing relief programs to their citizens to help alleviate the financial strain as a result of the COVID-19 pandemic. This threat actor, however, targets US relief efforts and the citizens who need it most. This email campaign uses the logo of the Internal Revenue Service (IRS) to bolster its credibility.

Figure 1: Email Preview

The threat actor made both the subject and sender information eye catching, as seen in Figure 1. The email appears to be from ‘IRS GOV’ regarding the subject “Tax Relief Fund,” which would be enough to gain the attention of anyone, especially those who may not have received their relief or need more. Upon clicking into the email, users are presented with the following message, as seen in Figure 2 below.

Figure 2-3: Email Body

Despite the image missing from this email sample, assumed to once have been a DocuSign logo based on the image description, the email may appear legitimate at first glance. The IRS has sent a secure document via DocuSign along with a security code to view it, but it must be used soon as it will “expire.” The email is also marked “High Importance.”

A closer look at the body of the email reveals many warning signs this email is a phish. Anyone acquainted with DocuSign would know this is not what an invitation from the service looks like. Not to mention there is odd spacing and capitalization found in the text – atypical for professional emails. There is also mention of a security code that must be used “before expiration,” a common social engineering tactic used to illicit a sense urgency.

The link found in the email, “View Shared Folder,” redirects users to the phishing site located at:

hxxp://playdemy[.]org/office/doc-new

Figures 4-5: Phishing Page and Confirmation Page

Figures 4-5 are examples of the first page users will see upon navigating through the link found in the email. The page is a simple DocuSign page prompting for the user’s email address in order to access the promised document. Visually there aren’t many differences compared to DocuSign’s website, other than the incorrect URL displayed in the address bar. However, the threat actor may have intentionally used a .org-based domain to make it appear safe, as many end users have heard .org top-level domains are “secure.”

Should a user proceed to enter their email address on this page, they are prompted once again to verify the information before being redirected to the next step of this attack.

Figures 6-7: AOL login page

The next step involves redirecting users to a phishing page based on their email provider. In Figures 6-7 above, we used a dummy AOL email and were redirected to an AOL phish. The attacker’s AOL login page rivals the look and feel of AOL’s — the only real difference is the incorrect URL in the address bar. The email entered in the first step is already pre-filled as well. This same occurs with other email providers inputted into the first step of the attack. Figures 8-10, for example, show the Gmail phish that users are redirected to if that was the email provider they entered.

Figures 8-10: Alternative Gmail Phish

Should a user enter an email address to proceed this far, the threat actor has made sure to ask for further compromising information, as seen in Figure 10: a recovery number or recovery email address per their back-up login information.

Figure 11: Final Destination

Regardless of the email address, and should the user enter this information, users are then redirected to an unexpected document; in lieu of the promised “Tax Relief Fund,” they see a completely unrelated academic paper hosted on Harvard Business School’s website. This is a common tactic, designed to confuse users into thinking there is nothing amiss, that perhaps this was a mistaken exchange or they received the wrong document in error and must wait for further contact.

Further analysis of the website utilized for this attack yielded further information on the attack and the actors behind it.

Figure 12: Open Directory

Upon navigating to the main domain, as shown in Figure 12, an open directory appears. While the file Chetos.php is password protected at present, the file 039434.php exposes a greater security threat that can be observed in Figure 13, a web shell.

Figure 13: WebAccess Shell

The beginnings of a malicious web shell start with an attacker methodically installing the malicious script for the shell on the targeted site, either by SQL injection or cross-site scripting. From there the web shell is utilized by attackers to maintain persistent access to a compromised website without having to repeat all the work of exploiting the same vulnerability they used the first time – generally, a backdoor. They can remotely execute commands and manage files that they abuse to carry out their attacks, such as a phishing attack.
As observed in Figure 13, investigation of the shell reveals files from the open directory are displayed, last modified 2020-04-24 by “owner/group” “njlugdc”, otherwise known as the attacker. The real guts of this attack, however, can be found within the directory path office/doc-new seen in Figure 14.

Figure 14: office/doc-new Directory

Within the directory are the many steps in what appears to be a simple phish. There are multiple email branded folders such as “a0l”, “earthl1nk”, “gma1l,” all of which help the threat actor target email clients. Each of these email branded folders host a phish that is specifically tailored to that brand, allowing for a more “authentic” experience that lull users into a sense of security.

Figure 15: Code Behind the Attack

Figure 15 demonstrates the code behind the attack that sanitizes user input to determine which of these phish a user is redirected to, along with the associated email brand logo to display during the redirect process.

Figure 16: Threat Actor Emails Exposed

Within the files contained in this web shell, the threat actor’s emails are displayed. Figure 16 shows the code of the Email.php file and information exfiltrated from users during the phishing attack that are sent to:
techhome18[@]gmail[.]com
we.us1[@]protonmail[.]com

Although the identity of the attacker behind this IRS phish is unknown, it is evident they took care to carefully craft this attack and chose to exploit a current event that is closely followed by Americans in an attempt to successfully steal as many log-in credentials as possible.

Network IOCIP
hxxp://playdemy[.]org/office/doc-new206[.]123[.]154[.]15

 

 

All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.
The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.

Phishers Continue to Spoof WebEx

By Kaleb Kirk, Cofense Phishing Defense Center

Last month, the Cofense Phishing Defense Center (PDC) observed a new phishing trend wherein threat actors spoofed WebEx pages to harvest Office365 (O365) credentials. Since the posting of the original blog, the PDC has seen an increase in the number of similarly themed WebEx phishing attacks, yet another example of attackers leveraging the rapid shift to remote work in light of COVID-19 concerns. As many organizations and their workforce are increasingly dependent on remote working tools and solutions, reducing the attack surface (the number of different approaches a threat actor can use to enter or extract data) of such online platforms and services is becoming even more critical.

Attackers know this and are constantly looking at ways to circumvent detection by secure email gateways and position themselves between users and legitimate services. The WebEx phishing campaign is a prime example, slipping past email protection to dupe users into providing their credentials out of fear they will be unable to use the service and perform their job otherwise.  It’s therefore not a surprise the PDC has seen an increase in phishing attacks that spoof legitimate, business critical services.

While this blog focuses on a new phishing campaign imitating WebEx, this style of attack can and has taken multiple forms, mimicking many different legitimate web services. Luckily however, once an end user knows some of the telltale signs,  it’s often easy to identify what is truly legitimate and what is fake.

Figures 1-2: Email Body

Upon an initial glance, this email may appear innocuous enough. It has the look and format one would likely expect when receiving an email from Cisco. The style is professional, the layout of the email isn’t mangled or chaotic, and it appears legitimate – an intentional and easy tactic to pull off. All the threat actor required was a real WebEx email to copy from in order to duplicate the style and alter select elements for nefarious purposes. The sender address appears to come from WebEx. However, this is what is known as the “friendly” from address – while the recipient sees the displaying address, which appears to be authentic, the email headers reveal a very different story. The problem with a “friendly” sender address is that it is easily spoofed by attackers; it’s a well-known, simple trick designed to convince the recipient that an email is legitimate.

Looking beyond simple aesthetics, however, other indicators of phishing are evident. The subject line indicates there is an issue with SSL certificates that requires the user to sign in and resolve. This is referenced further in the body of the email, providing a sense of legitimacy and enticing them to open the email and read it.

The wording of the email also employs scare tactics that are prevalent in phishing attacks. The recipient is informed there is a problem that has caused their service to become deactivated and the user must log-in and authenticate by clicking the link. Verbiage like this is often used to coerce the end user into clicking on a link or attachment in haste before they have time to fully think it through – a key tactic used by threat actors in phishing campaigns.

Finally, the link itself reveals something else is fishy about this alert. Hovering over the button shows the embedded link is not, in fact, a WebEx page, but a SendGrid link, a legitimate customer communication service used by marketing professionals. SendGrid links are commonly used in phishing attacks, as they require minimal effort.

Figure 3: Phishing Page, Step 1

Upon clicking the SendGrid link, the user is redirected to a phishing page, as seen in Figure 3. The only difference between a legitimate WebEx login page and this phishing page is the URL itself, suggesting the attacker conducted some form of web scraping to create an intentionally benign looking and familiar login page for the end user. Web scraping, essentially, is the practice of using a tool to automatically copy data from a website and create a convincing copy.

Figure 4: Phishing Page, Step 2

Deception quickly falls apart when reviewing the URL, however; while designed to look like the actual URL, there actually isn’t a portion that includes ‘webex.com’. The numerous dashes, coupled with one very long word followed by ‘index.php’ is not reflective of a professional link, suggesting the phishing URL was registered to appear legitimate at first glance. While phishers commonly make a valiant effort for their pages to look legitimate, looking at the address bar generally reveals if it’s legitimate. Misspelling, similar looking words and strange top-level domains are common tricks used by attackers to guile end users for just long enough to not question it.

While the initial phishing page only requests the user’s email address, the following page then changes URLs from “index.php” to “step2.php” and asks for the user’s password- this is another indicator the site is not legitimate, as the specific internals of which php file is being invoked for this webpage would be usually be hidden to the user.

Figure 5: Final redirect to official WebEx login page

As the final stage of attack, when the user enters their credentials on the page shown in Figure 5 above, the user is then redirected to WebEx’s real sign-in page. At this point, the malicious actor now has the user’s credentials, but it is in their best interest to ensure the user is unaware that a successful credential phishing attack occurred, giving the threat actors time to make use of newly stolen log-in details. The final redirect to WebEx’s legitimate log-in page may make the end user believe there was a log-in error and they need to log-in again. A common theme in a many phishing attacks is appealing to and preying on the feeling that nothing is amiss and there is nothing to question about the experience. In the meantime, threat actors gain precious time to do damage while the end user moves on with his or her workday.

Figure 6: Open Directory

A final interesting finding about this phishing campaign is the main domain itself, which reveals an open directory. This open directory shows the files included in the phishing page: images, fonts, .css files, and more. Although finding this directory was easy, it isn’t necessary to hide it, as most end users will only go through to login rather investigating into the internals of the site. However, it must be noted no professional website allows access to its file directories in this way. If reached, it is an almost sure-fire way of immediately identifying a phish.

Network IOCIP
hXXps://cert-ssl-global-prod-webmeetings[.]com/da4njy=/idb/saml/jsp/index[.]php137[.]135[.]110[.]140

 

How Cofense Can Help

Visit Cofense’s Remote Work Phishing Infocenter to stay up to date as threats evolve. Our site is updated with screenshots and YARA rules as we continue to track campaigns.

All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.
The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.

Staff Members’ Inbox Positive for Coronavirus Themed Phish

By Ashley Tran, Cofense Phishing Defense Center

From prime ministers, members of congress to celebrities and staff of nursing homes — many have been affected by COVID-19. And the worst part? Threat actors know this and are heavily weaponizing this pandemic, exploiting the fears and concerns of users everywhere. The Cofense Phishing Defense Center (PDC) has observed a new phishing campaign found in environments protected by Microsoft and Symantec that not only impersonates a company’s management but also suggests that a fellow employee has tested positive for the disease, urging users to read an enclosed malicious attachment posed as “guidelines” or “next steps.”

As we have seen before and noted in previous Cofense blogs and media stories, Coronavirus themed phishing attacks are running rampant and attacking users across all industries. Although the attacks vary in method, the main takeaway is the same: all users must exercise the utmost caution and restraint in the face of emotionally jarring emails.

Figures 1-3: Email Bodies

The PDC has found multiple instances of this attack and a trend among them all. As demonstrated in Figures 1-3, the email subject lines are relatively similar: “Staff Member Confirmed COVID 19 Positive ID,” followed by a random string of numbers and that day’s date. The emotion these subject lines evoke in users are also the same: fear and curiosity. Emails appearing to be a “Team Update on COVID 19” and bearing their company’s name can convince end users to believe the email was sent internally. However, the true senders are revealed via the return paths:

Maga[@]tus[.]tusdns[.]com and ungrez[@]ssd7[@]linuxpl[.]com

Admittedly these emails would appear suspicious to most, but the threat actor is relying on the emotional subject line to overcome logic and push users to read just the first line of the sender information and nothing more.

The bodies of the emails have more variety and are worded differently, but the same main point: a fellow employee has the virus, so read this guideline we’ve attached to get more details or at least learn the “next steps” to take. To top it off the email is signed by “Management.”

The true part of this attack lies within the HTML file found in the email.

Figure 4 shows that the attachment has been detected as malicious by a multitude of services, however users won’t see this when they read the email.

Figure 4: VirusTotal Analysis

Figure 5: Phishing Page

Upon opening the attachment users are presented with a generic Microsoft login page, a frequently targeted brand. The difference with this phish, however, is the threat actor has superimposed the login box over a blurred document that may appear to users as the previously mentioned “guidelines” lending an even greater sense of legitimacy.

The email of the recipient is automatically appended to the username field via code in the HTML. In fact, the threat actor has painstakingly put the base64 for each of the recipient’s email addresses, which is then translated to a readable format when interacting with the phish. This snippet of code can be observed in Figure 6.

Figure 6: Email Bodies

Once a user navigates to the next page and inputs their password, the information is then sent to the compromised site:

hxxp://tokai-lm[.]jp/style/89887cc/5789n[.]php?98709087-87634423

This exchange of information can be viewed by opening developer tools on any browser and navigating to the networking tab as shown in Figure 7.

Figure 7: Phishing Page

The code found within the HTML file that hosts the phishing content employs typical malicious tactics. For example, as seen in Figure 8, the code does not look like a typical HTML code. This is because the threat actor has attempted to obfuscate their code, to make analysis as well as detection harder. However, this is nothing new for phishing campaigns that choose to utilize a HTML file. De-obfuscating the code and revealing some its methods is not difficult.

Figure 8: Obfuscated Code

To begin, the code is notably broken into different parts. Each of these parts may stand out to anyone with an eye for encoding as being Hex text and base64. These both can easily be decoded back into their original form, the true HTML code, by utilizing tools such as RapidTables and Base64 Decode.

Figure 9: De-obfuscated Code

After de-obfuscating the code, the true HTML is seen in Figure 9, revealing the threat actor has compromised, or at the very least utilized, a compromised site to host the style sheet for their phish:

hxxp://ibuykenya[.]com/vendor/doctrine/styles[.]css

Figure 10: Open Directory with Phish Resource Files

The following is the directory which the threat actor has used to store the style sheet for the phish, along with what appears to be two additional files, based on their last modified dates.

Within the code, the image seen in the background of the document can also be recovered. The image is hosted on ImgBB, yet another relatively benign image hosting site to which threat actors flock to host images for their attacks.

hxxps://i[.]ibb[.]co/dMcjCWC/image[.]png

Figure 11: Document Preview from Phish

Upon closer observation, the title of the document can be obtained. With a quick search, the image the threat actor has used to further legitimize this login page in the eyes of the user can be linked back to the legitimate document found in Figure 12.

Figure 12: Legitimate Document Utilized by Threat Actor

All these steps – the social engineering, the obfuscated code, use of official COVID health advisories and more-are designed to ensure users don’t detect the phishing attack is in progress. This phish also demonstrates the attacker’s need to employ layered techniques designed to avoid detection by email gateways, as well as the incident responder’s need for the right investigative tools to properly analyze, detect and quarantine this threat.

Network IOC IP
hxxp://tokai-lm[.]jp/style/89887cc/5789n[.]php?98709087-87634423150[.]60[.]156[.]116

 

How Cofense Can Help

Visit Cofense’s Coronavirus Phishing Infocenter to stay up to date as threats evolve. Our site is updated with screenshots and YARA rules as we continue to track campaigns. (edited) 

All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.
The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.

Targeted Attack Uses Fake EE Email to Deceive Users

By Kian Mahdavi and Tej Tulachan, Cofense Phishing Defense Center

The Cofense Phishing Defense Center (PDC) has discovered a spear-phishing campaign designed to defraud corporate executives’ payment details by spoofing EE, a well-known UK-based telecommunications and internet service provider.  These spear phishing messages were reported to the Cofense PDC by end users whose email environments are protected by Microsoft 365 EOP and Symantec. This new, targeted campaign shows that while exploiting well-known telecommunications brands is nothing new, such phishing emails continue to go undetected by popular email gateways designed to protect end users, leading to possible theft of prized corporate credentials

Figure 1: Email Body

Threat actors sent a targeted email to a few executives, including one at a leading financial firm, with the subject line reading ‘View Bill – Error’ from a purchased top-level domain (moniquemoll[.]nl). These details in and of themselves may raise red flags to eagle-eyed recipients, as EE’s trademarked name isn’t included in any part of the full email address.

The malicious URL inserted within the text is:

hXXps://fly-guyz[.]com/ee[.]co[.]uk[.]edcnymdsqmnydqnyo

The vague email indicates ‘we’re working to get this fixed’. At no point does the email give an indication what this error is. As we read on, the second hyperlink states ‘view billing to make sure your account details are correct’ to entice the recipient to click the phishing link.

The threat actor fails to include the correct registered office address, evident towards the bottom of the email. Once the threat actor’s social engineering does the trick and the user clicks one of the links, they are redirected to a phishing page.

Noted in Figure 2 below is the trusted HTTPS protocol (also displayed as the green padlock) within the URL, giving false hope to the user that network traffic is being encrypted, ensuring all data transferred between the browser and website is secure and not being eavesdropped on.

However, the threat actor even went to the trouble of obtaining SSL certificates for the domain to further gain end users’ trust. In fact, it has become much easier for site owners, including fraudsters, to obtain these certificates.

Figures 2 and 3: First and second phishing pages

The peculiar aspect is the message in which the threat actor included: ‘You will not be charged’ to reassure recipients and trick them into providing their payment information.  The user is then automatically redirected to the legitimate EE website, as displayed below in Figure 4, to avoid suspicion. This is a common tactic to make the user believe the session timed out or their password was mistyped.

Figure 4: Legitimate Redirect Login Page

At the time of writing, the phishing page is still live and active. To further validate the analysis of the investigation, we decided to input some fake credentials, allowing us to verify the transmitted TCP requests and redirects to the fraudster’s domain at hXXps://kbimperial[.]com/data[.]php.

Figure 5: TCP Retransmission Packets

Indicators of Compromise:

Network IOCIP
hXXps://fly-guyz[.]com/ee[.]co[.]uk[.]edcnymdsqmnydqnyo/
hXXps://kbimperial[.]com/ee[.]co[.]uk[.]edcnymdsqmnydqnyo/logins
hXXps://kbimperial[.]com/data[.]php?
104[.]31[.]82[.]7
104[.]31[.]83[.]7
35[.]208[.]71[.]62

 

All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats.
The Cofense® and PhishMe® names and logos, as well as any other Cofense product or service names or logos displayed on this blog are registered trademarks or trademarks of Cofense Inc.