Cybercriminals Exploit Foxit PDF Reader to Deploy ValleyRAT Malware
In a sophisticated cyberattack campaign, threat actors are leveraging the Foxit PDF Reader to distribute the ValleyRAT malware, targeting individuals seeking employment. This operation employs deceptive tactics to infiltrate systems and exfiltrate sensitive data.
Deceptive Tactics Targeting Job Seekers
Cybercriminals have devised a method to deliver malware by masquerading malicious files as legitimate recruitment documents. The campaign, identified as ValleyRAT, specifically targets job seekers through emails containing counterfeit job offers and company materials.
The attack vector involves compressed archive files with professional-sounding names like Overview_of_Work_Expectations.zip or Candidate_Skills_Assessment_Test.rar. When recipients open these files, they inadvertently execute a remote access trojan, granting attackers control over their systems.
Exploitation of Foxit PDF Reader
Central to this campaign is the exploitation of the widely-used Foxit PDF Reader. Within each malicious archive lies an executable file disguised as the Foxit application, complete with its recognizable icon. This subterfuge leads users to believe they are opening a standard PDF document, unaware that they are initiating malware designed to commandeer their computers.
Technical Mechanisms of the Attack
Beyond the initial deception, attackers employ a technique known as DLL side-loading to activate the malicious payload stealthily. Trend Micro researchers observed a significant increase in ValleyRAT detections in late October, highlighting the campaign’s effectiveness.
The infection chain is meticulously crafted:
1. User Interaction: The user clicks on the renamed Foxit executable.
2. DLL Side-Loading: A malicious library (msimg32.dll) is loaded via Windows’ file search mechanism.
3. Batch Script Execution: A batch script extracts a concealed Python environment from seemingly benign document files.
4. Malicious Script Deployment: The Python interpreter downloads and executes a malicious script containing shellcode.
5. ValleyRAT Deployment: The shellcode deploys the full ValleyRAT trojan.
The malware establishes persistence by creating registry entries, ensuring it remains active even after system restarts.
Capabilities and Impact of ValleyRAT
Once installed, ValleyRAT provides attackers with comprehensive control over compromised machines. The trojan can monitor user activity, steal sensitive information from web browsers, and extract valuable data from infected systems. Notably, the malware targets password information and login credentials stored by popular browsers, posing significant threats to personal financial security and identity protection.
Broader Implications and Recommendations
While job seekers and human resources professionals are the primary targets, the campaign continues to evolve, potentially reaching a broader audience. This underscores the necessity for heightened vigilance when handling unsolicited emails and attachments.
Preventive Measures:
– Verify Sources: Confirm the authenticity of emails and attachments, especially those related to job offers.
– Update Software: Regularly update applications like Foxit PDF Reader to patch known vulnerabilities.
– Employ Security Solutions: Utilize reputable antivirus and anti-malware programs to detect and prevent such threats.
– Educate Users: Raise awareness about social engineering tactics and the importance of cautious behavior online.
By adopting these measures, individuals and organizations can mitigate the risks associated with such sophisticated cyber threats.
