Threats Tagged 'chm dropper'

On April 11, 2026, researchers analyzed a CHM file (api_reference.chm) tagged as Kimsuky that initiated a three-stage attack chain. The C2 server at check[.]nid-log[.]com had directory listing enabled, allowing recovery of complete source code for all payload stages: a 6,338-byte VBScript performing system reconnaissance and establishing persistence via scheduled task, a 449-byte VBScript bridge to PowerShell, and a 6,234-byte PowerShell keylogger with clipboard monitoring and timed exfiltration. The infrastructure included 79+ domains across 5 C2 IPs spanning Korean VPS providers. The server responded with "Million OK !!!!" signature, matching previously documented Kimsuky infrastructure while showing upgraded Apache/PHP stack. The operation targeted Korean Naver users through credential phishing and tax authority impersonation, with infrastructure linked to previously documented Kimsuky campaigns via shared DAOU Technology subnets.

In March 2026, a China-nexus threat actor launched a sophisticated campaign targeting countries in the Arabian Gulf region, exploiting renewed Middle East conflict themes within 24 hours of escalation. The attack utilized Arabic-language lures depicting missile strikes and employed a multi-stage infection chain beginning with weaponized ZIP archives containing malicious LNK and CHM files. The campaign deployed a heavily obfuscated PlugX backdoor variant through DLL sideloading, with components using control flow flattening and mixed boolean arithmetic techniques. The backdoor supports HTTPS command-and-control communications, DNS-over-HTTPS resolution, and multiple plugins for system manipulation. Based on tools, techniques, and procedures including specific RC4 decryption keys and rapid geopolitical weaponization, the activity is attributed with medium confidence to Mustang Panda.

MediumMalwareBahrainKuwaitOman+3#china-nexus#destroyrat#arabian gulf