The Malware Holiday Ends—Welcome Back Geodo and Chanitor

CISO Summary

Even cybercriminals knock off for the holidays. Then in January, it’s back to work. We all have bills to pay.

This past holiday season, including the Russian Orthodox Christmas which fell on January 7, threat actors cooled their heels and malware campaigns dipped. But with the holidays over, threat actors are back in action. Chanitor malware campaigns are spiking, at even higher levels than a year ago, and Geodo/Emotet campaigns have been surging too.

Phishing Campaigns are Manipulating the Windows Control Panel Extension to Deliver Banking Trojans

By Aaron Riley and Marcel Feller

CISO Summary

Recently, CofenseTM has seen phishing campaigns that bypass email security using a .cpl file extension attachment. .CPL is the file name extension for items or icons appearing in the Windows Control Panel. These file extensions are vital for most Control Panel tools to function, making endpoint threat mitigation extremely difficult.

After evading controls and successfully executing on the endpoint, the .cpl file downloads a second-stage payload, which is typically a banking trojan. According to Cofense IntelligenceTM, most of these phishing campaigns are aimed at South American inboxes. As part of security awareness training (see Cofense PhishMeTM), organizations should condition users to identify and report .cpl files to avoid network infection.

Full Details

The Cofense Phishing Defense Center (PDC) has captured multiple phishing campaigns using a .cpl file extension attachment to bypass email security measures and download a second stage payload, which typically is a banking trojan. Cofense Intelligence has analyzed these campaigns and found that the majority of them are targeting South American citizens. Furthermore, to successfully communicate with the Command and Control (C2) infrastructure, the endpoint needs to mirror a South American computer’s settings like IP address, time zone, language pack, and keyboard settings.

The .cpl file extension is used for Control Panel tools with executable byte code. The .cpl byte code is the same across all PE32 binaries (such as .exe, .dll, .scr) within the DOS stub and is executed by control.exe. These file extensions have been used with campaigns that deliver banking trojans, most notably Banload. Cofense IntelligenceTM customers can view an analysis of Banload by logging in here. Figure 1 shows an email campaign that is used to deliver a .cpl attachment. The email is in Spanish and claims to come from ‘Servicio de Impuestos Internos,’ the Internal Revenue Service of Chile.

Figure 1 shows the email campaign used to deliver .cpl attachments.

The .cpl file attached to this campaign acted as a first-stage downloader, facilitating the retrieval and execution of a secondary payload. Figure 2 shows the HTTP POST to the C2 infrastructure during the preliminary communication. This HTTP POST contains the machine and username of the infected endpoint and is appended with a number sequence known to the C2. Figure 3 shows the fingerprinting data within the form values posted to the C2.

Figure 2 shows the HTTP POST and GET traffic originating from the .cpl file.

Figure 3 shows the information gathered by the .cpl file to fingerprint the infected machine.

After the initial connection is successful, the binary then connects to a hardcoded payload location for the second stage. Notice in Figure 2 that there was a GET request for another payload. By effectively expanding the detection surface, this two-stage download and execution actually increases the likelihood of C2 interruption.

While analyzing the .cpl binaries’ network traffic, Cofense Intelligence identified a custom User-Agent string that can be turned into network alerts within a Security Event Information Management (SEIM) system. Figures 4 and 5 shows the two different user agents connecting to the same host. Based on packet analysis, these custom User-Agents would suggest the threat operators are limiting access to their C2 infrastructure.

Figure 4 shows the User-Agent for the HTTP POST.

Figure 5 shows that the User-Agent value is ‘LA CONCHA DE TU MADRE,’ a Spanish expletive whose cleaned-up meaning is ‘the shell of your mother.’ This User-Agent string lends further credence to the idea that the User-Agent string is used to mitigate access to the C2 infrastructure and help determine the stage of infection. However, leaving such an obvious indicator for the security infrastructure to identify gives the impression this was an amateur operator.

Figure 5 shows the User-Agent string for the GET request made by the .cpl file.

After execution, this .cpl attachment followed trends and called for the second-stage payload to execute a sample of OverByte ICS Logger. This keylogger was configured with multiple modules to target and gather banking information from the endpoint. Figure 6 shows the malware family name within the memory strings. Figure 7 shows the multiple modules configured within this binary.

Figure 6 shows the malware family name within the memory strings.

Figure 7 shows the multiple modules that were used to configure this binary.

This sample of OverByte ICS Logger went after banking information, specifically South American banks. The banking information gathered includes usernames, passwords, Personal Identification Numbers (PINs), and any element ID that was selected during the login process. Element IDs are unique identifiers that facilitate accurate targeting for JavaScript and CSS. Use of element IDs means modifications to the page can be made accurately, provided the author adheres to the standards.

After gathering the information, this sample then sends it to the C2, which in this case was the same as the second-stage download. This OverByte ICS Logger persisted on the machine and gathered banking information at predetermined times to be sent to the C2. Figure 8 shows a list of banks (redacted) in the memory strings of the running sample.

Redactions in Figure 8 show where the references to banks would be within the memory strings.

The use of .cpl file extensions are a necessary item for most Control Panel tools to function properly. The operating system’s need for this extension makes the mitigation and remediation extremely difficult within the security stack. The trend to deliver banking trojans to the endpoint is a looming threat of these extensions. Educating end users on how to properly identify and report these types of files when they are encountered is the best way to avoid this type of infection on a network.

To stay abreast of the latest phishing and malware trends, sign up for free Cofense Threat Alerts.

Indicators of Compromise

Observed URLs: hxxps://gentsilen[.]com[.]mx/cl/factura[.]php?folio=1&Importancia=Urgente&descarga=true&impuestos=servidor_alerce&site=www[.]sii[.]cl

185-35-139-197[.]v4[.]as62454[.]net

185-35-139-190[.]v4[.]as62454[.]net


Observed IPs:

185[.]35[.]137[.]85

185[.]35[.]137[.]80
185[.]35[.]139[.]190

 

Observed Files:
File Name: Sii_Documento_TVLN11.zip
MD5: 9ace92029ad8f1516b141de7022d3c42
SHA256: 15f107a75f166b519ce7ca8da094c9b915aa7a6b44fade360535e5112bfd2f5f
File size: 718,191 Bytes

File Name: Sii_Documento_TVLN11.zip
MD5: 7e8edf93d3565c4eacbbea19615d21d3
SHA256: 5c908e77c0e2f14f757d9b0b2d63f661bc277eb70e8caa46d85f038cb87f2c2b
File size: 717,935 Bytes

File Name: Sii_Documento_K3YLT2WJNU.cpl
MD5: 541a3aaf1f70c473f0018c9aa951fb9a
SHA256: d9e3913e5e6d151dd487d9e174c9e3e73d1883ea0c78cf97909caaf76dd4e618
File size: 761,902

File Name: mTjdyis.exe
MD5: b2218df5c3373a9a1b619e53281e9806
SHA256: 681ccc9e5bab3a23b3ce31fdc1eb8db268e79e1521e748d8f8c951d10a3a096c
File size: 400.872 Bytes

File Name: shfolder.dll
MD5: 037bb84e2aab7ab4df2e0c752c61233a
SHA256: b8af00e8e89583a529284496949cc2c10684b035
File size: 42.466.735 Bytes

 

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.

Exploiting an Unpatched Vulnerability, the Ave_Maria Malware Is Not Full of Grace

CISO Summary

CofenseTM has seen a rise in phishing campaigns designed to deliver a type of stealer malware called Ave_Maria. It contains a capability, DLL hijacking, that uses a vulnerability with no forthcoming fix. With origins in a publicly available utility, DLL lets Ave_Maria gain greater admin privileges and avoid detection, then steal information so it can download additional plugins and potentially other payloads. This malware can bypass detection and privilege restrictions on many endpoints.

The Vjw0rm Malware Does It All. Here’s What to Watch For.

CISO Summary 

It’s called the Vengeance Justice Worm (Vjw0rm), but think of it as the Leatherman tool of malware. Vjw0rm wreaks havoc in highly versatile ways: information theft, denial of service (DoS) attacks, and self-propagation to name a few. CofenseTM has spotted this hybrid threat—a cross between a worm and a remote access trojan (RAT)—in a recent phishing campaign dangling a banking lure.   

In 2018, Cheap and Easy Malware Flooded Corporate Inboxes

CISO Summary

Sometimes it’s the simple things that make life hard. In 2018, over 2/3 of unique malware campaigns Cofense IntelligenceTM observed were simple, inexpensive “stealers” or remote access trojans (RATs). With exceptionally low barrier-to-entry—an email account or website can handle distribution and communication—these malware types make data theft a viable career choice for threat actors without the skills to use more advanced varieties.

Domain Fronting, Phishing Attacks, and What CISOs Need to Know

CISO Summary

Cofense IntelligenceTM is seeing continued use of a cyber-attack technique known as domain fronting. It’s yet another way hackers conceal their malicious activity, in this case using work-arounds to evade security controls and gain access to command-and-control (C2) infrastructure (scroll down for a technical explanation).

Cozy Bear, the Russian threat actors, used similar tactics when they hacked the Democratic National Committee in 2016. Today, businesses are dealing with phishing and malware attacks that domain fronting enables.

While Google and Amazon have taken measures in their CDNs to curtail this trend, we have seen an uptick in C2 infrastructure hosted in Cloudflare CDNs (figures 2-4 below). Last month, Cofense Intelligence reported that Cloudflare domains were being abused by threat actors to launch malware attacks on finance departments.

Why is this a problem?

If part of your cyber defense strategy is using a web gateway to prevent employees from visiting non-categorized sites, or blocking based on a threat intelligence feed of known C2 hosts, you can’t practically block access to a CDN without disrupting Internet-reliant business processes.

CISOs should make sure their SOCs are aware of the problem when reviewing suspicious emails reported by employees. While we wait for traditional cyber perimeter controls to catch up to this threat, a phishing training and reporting program (see Cofense PhishMeTM and Cofense ReporterTM), plus a phishing-specific response capability (see Cofense TriageTM and Cofense VisionTM) is the last line of defense.

Full Details

Malware operators continue to use domain fronting to bypass security measures and reach their command and control (C2) infrastructure hosted on content delivery networks (CDN). This C2 communication technique is difficult to defend against due to the large overhead required and strong reliance on CDNs. Certain CDN providers have recently changed their network schemes and policies in response to this threat, however, domain fronting is still possible through some of the minor CDN hosts.

Domain fronting is the exploitation of an encrypted connection to a CDN to gather web resources otherwise blocked by network security measures.

  • First, the client initiates a connection to a legitimate domain (front domain) via HTTP.
  • Second, the originating connection request is read in the clear and is inspected by network security measures.
  • Third, an HTTPS connection is created when the connection is encrypted with an SSL layer, allowing the contents of the traffic to bypass inspection.
  • Finally, The HTTP Host header is read by the server for the resources needed.

The HTTP host header, for this technique, is manipulated to gather resources from a nefarious site on the same CDN. The connection to the manipulated HTTP host header inside the encrypted traffic bypasses network security measures that don’t decrypt the traffic.

For domain fronting to work, the nefarious site and the legitimate site must both be hosted by the same CDN. The ability to pull resources from other sites works because of the inner networking of the CDN and the routing access availability to other parts of their hosting environment. This technique is also utilized with The Onion Router (TOR) node bridges and the meek protocol. The Russian hacker group that breached the Democratic National Committee in 2016, APT29, also known as Cozy Bear, used the TOR meek protocol for their C2 infrastructure communication. Figure 1 gives an overview of this technique.

Figure 1 Technique of domain fronting to bypass inspection.

Google and Amazon CDNs mitigated this technique by preventing any routing from one owner’s site to another. This is done by matching the HTTP host header with the original server name indication (SNI) request, implemented in late April and early May 2018. Since then, Cofense Intelligence has seen an increase in the number of phishing campaigns delivering malware in which the C2 was hosted by Cloudflare.

Figure 2 shows the contrast in Cloudflare C2 seen used by malware before and after May 2018, when Google and Amazon imposed barriers to such activity on their CDNs.

Figure 2 Analyzed C2’s hosted on Cloudflare before and after May 2018.

Figure 3 shows the breakdown of malware families that have used Cloudflare for C2 infrastructure after May of this year.

Figure 3 Malware families utilizing C2’s hosted by Cloudflare since May 2018.

Figure 4 shows the number of different hosts hosted by Cloudflare to which each malware family connects.

Figure 4 Number of C2’s hosted by Cloudflare for each malware family.

Domain fronting has been used by hacktivists and threat actors like APT29 to conceal their malicious activity. CDNs are starting to take the necessary steps to mitigate domain fronting by negating routing from one owner’s site to another, but this ability still persists because it allows for routing to take place among a single owner’s sites.

Defending against this type of communication is a heavy lift for the information technology team. Stopping a malicious email campaign within the email security stack before it gets to the end user’s inbox, and training users to identify phish that do reach their inboxes, are keys to helping mitigate this evasive exfiltration techniques like domain fronting.

Learn more about how Cofense stops active phishing threats.

 

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.

TV-License Phishing Scam Tricks UK Users Into Giving Personal Information

Cofense Intelligence recently observed a new phishing scam making the rounds in the United Kingdom. It poses as the TV licensing authority better known as the British Broadcasting Corporation. The premise behind the scam is to trick the user into believing that he or she is breaking the law by not owning a valid license to receive TV, a criminal offense in the UK with a maximum penalty of a £1000 fine plus any legal costs incurred during prosecution.  

2018: A Reverse-Course for Ransomware

By Mollie MacDougall

The overall number of ransomware campaigns and active families has declined precipitously in 2018 as compared to last year, almost certainly due to multiple deterrents and a better alternative for profit-minded hackers. This reverse-course in ransomware trends follows years of sustained growth in the number of ransomware families and unique campaigns. Still, ransomware attacks make headlines and will likely continue into next year.