CLEARFAKE
CLEARFAKE is the term used to describe the malicious in-browser JavaScript framework deployed on compromised webpages as part of drive-by compromise campaigns to deliver information stealers. It has the potential to impact all sectors. CLEARFAKE’s technique involves tricking users into initiating fake updates, ultimately leading to the installation of malicious payloads on their systems. The fake updates are often browser-related update prompts (Chrome or Safari) that appear on compromised websites through the use of JavaScript injections.
The CLEARFAKE campaign begins with a user browsing to a compromised webpage, typically a WordPress site. There appears to be no forced social engineering to persuade users to navigate to the compromise webpage; instead, CLEARFAKE acts as a drive-by compromise waiting for users to land on the page.
In May 2024, Kroll observed a new method that CLEARFAKE leverages to trick users into running malicious code on behalf of the threat actors, bypassing the initial download of files that would have previously conducted malicious activity. In these cases, Kroll observed the victim being redirected to a malicious webpage (in the format “{domain}/lander/powershell/index.html"), which is disguised as a browser error. Although it has a similar theme to previous fake update iframes, the decrease in the quality of the lure is notable because it does not appear to mimic any legitimate error that Chrome would produce
Initial Browser Error Screen
Follow-On Browser Error Screen With Instructions to Victim
(Source: Kroll. For a full technical analysis of this issue, view our article)
IDATLOADER (aka HIJACKLOADER)
Similarly, Kroll observed an uptick in IDATLOADER infections stemming from drive-by-download, used to execute information stealers on the victim machine.
In June, Kroll’s MDR team responded to an incident in which suspected malware was exhibiting strange download behavior. After successfully containing and resolving the incident, Kroll’s CTI team investigated further, uncovering a complex infection chain involving many layers of obfuscation being used to deliver IDATLOADER. Had the infection not been detected and stopped, it would have ultimately resulted in the deployment of information-stealing malware.
As the investigation unfolded, it was discovered that the IDATLOADER infection hinged on using Microsoft’s mshta.exe to execute code buried deep within a specially crafted file masquerading as a PGP Secret Key, also making use of novel adaptations to common techniques and heavy obfuscation to hide the malicious code from detection.
Additionally, Kroll identified a sideloading technique that leveraged Borland Package Library (BPL) files instead of regular dynamic link libraries (DLLs), which Kroll calls “BPL sideloading.” At time of writing, there is no MITRE sub-technique for BPL sideloading. Kroll has requested that a new sub-technique to be added to the MITRE framework.
View our article for more insights on this issue