PULSE NAME
Pretexting-Based Targeted Intrusion: Analysis of Facebook Reconnaissance and Software Tampering Attacks
WHITE APT37 AlienVault 2026-04-14 Modified: 2026-04-14
21
IOCs
MEDIUM VOLUME
APT37 conducted a sophisticated social engineering campaign utilizing Facebook accounts claiming locations in Pyongyang and Pyongsong, North Korea, to conduct reconnaissance and build trust with targets. After establishing relationships through Facebook Messenger, the threat actor migrated conversations to Telegram and employed pretexting tactics, claiming to share encrypted PDF documents containing military weapons information. Victims were persuaded to install a tampered Wondershare PDFelement installer that executed embedded shellcode for initial compromise. The attack chain delivered follow-on commands through a JPG-disguised payload hosted on a compromised Japanese real estate website. The malware abused Zoho WorkDrive OAuth2 APIs as C2 channels, exfiltrating screenshots, documents, system information, and audio files. The campaign employed multiple evasion techniques including code cave injection, process hollowing into legitimate dism.exe, XOR encryption layers, and fileless in-memory execution.
Indicators of Compromise (4 / 21 total)
All FileHash-MD5 FileHash-SHA1 FileHash-SHA256 IPv4 URL domain email hostname
TYPEINDICATORDESCRIPTIONCREATED
FileHash-SHA1 4137911f14563fdf7500159ee7a386d9c54bbdae 2026-04-14
FileHash-SHA1 441603f740667fd5b4365b880b55a6cb6991cd96 2026-04-14
FileHash-SHA1 6625f25a82a9739476402a759a514a59f822f5d8 2026-04-14
FileHash-SHA1 d0f8b7885e65a2d0714f91f7275d100bca25a886 2026-04-14