Cofense Intelligence™ recently identified a TrickBot campaign that was noteworthy not for its exceptional guile or novel technique, but rather for its lack thereof. Absent any images or convincing textual narrative, the campaign lacks all the hallmarks of this TrickBot distribution group’s modus operandi.
Cofense Intelligence™ has uncovered a recent AZORult stealer phishing campaign that delivers the malware via malicious attachments. Older versions of AZORult stealer have been delivered via intermediary loaders, typically Seamless or Rammnit malware. In this latest campaign, the attached documents use multiple techniques to download and execute an AZORult sample, indicating a shift by the threat actors behind the campaign to adopt more evasive delivery techniques.
By Brendan Griffin and Max Gannon
A classic phishing technique involves timing attacks to match major holidays and other global and regional events. One example of this scenario in a phishing attack captured by Cofense Intelligence™ delivering the Geodo botnet malware on July 3, 2018. In this attack the threat actor appeals to the patriotic nature of the Fourth of July holiday and recipients’ sense of patriotism in its content. In these messages, the attacker reminds the recipient of the sacrifices of American service member as part of a narrative designed to entice victims to click on the link in the messages to access an Independence Day-themed greeting card. In doing so, the victim will receive a Microsoft Word document equipped with macro scripting designed to download and run the Geodo malware.
Cofense Intelligence™ recently observed a sample of Zeus Panda which, upon further research, revealed the malware has been increasingly employing a very creative tactic. This crafty malware variant distracts its victims while quietly draining the victims’ bank accounts, even those accounts that employ additional security mechanisms such as Multi-Factor Authentication. After transferring funds, the malware then masks any evidence that the illicit transactions ever occurred. This tactic ensures that victims with the deepest pockets will remain in the dark as their bank accounts are silently liquidated.
Since this April, Cofense Intelligence™ has observed a sustained increase in the financially motivated targeting of United Kingdom-based users with phishing lures imitating brands like Her Majesty’s Revenue & Customs (HMRC), Lloyds Bank, and HSBC Bank. The most common final payloads delivered by these campaigns are designed to compromise victims’ financial accounts and provide illicit access to financial information. This surge in targeting almost certainly represents a stage in the “whack-a-mole” strategy long employed by threat actors: expand campaigns against a segment of the vast vulnerable attack surface until those users catch on to the threat, then move to the next target.
On Monday May 28, 2018, during routine operations, Cofense Intelligence™ identified traits across several campaigns that indicated they were linked. In fact, this discovery helped to reveal a sprawling criminal enterprise that uses linked infrastructure to host nearly 100 domains, along with corresponding malware campaigns.
Recently, Cofense IntelligenceTM reported on a new mechanism used to distribute Dreambot malware, where a malicious page impersonating Microsoft Office Online entices victims to download the banking trojan. We have noted a similar delivery technique in the distribution of a TrickBot sample where targets are required to download a “plugin” to interact with a PDF, adding to the iteration of purported “plugin” downloads for malware delivery. The detailed campaign leverages social engineering techniques to gain access to victims’ sensitive information and also contains code obfuscation to evade detection by security technologies.
Cofense Intelligence has observed several recent Sigma ransomware campaigns that demonstrate either a new iteration or a fork of this malware. Prior to these new campaigns, the actors behind Sigma stuck rigidly to two very distinct phishing narratives, as detailed in Cofense’s recent blog post, and relied on the same infection process. With these newly observed changes, Sigma’s operators have eliminated various infrastructure concerns and improved the UX (User eXperience) of the whole ransom process, representing the first major shifts in Sigma tactics, techniques and procedures (TTPs).
Cofense Intelligence recently identified a large Sigma ransomware campaign that contained significant deviations from the established TTPs employed by the actors behind this prolific piece of extortionware. These changes improve Sigma’s A/V detection-evasion and demonstrate new social engineering tactics intended to increase the likelihood that a targeted user would open the phishing email and its malicious attachment.