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-SHA256 3ecb8632582982f5ea4cef6b32ac468bd43c61896b5de57416c8100f8ab90102 2026-04-14
FileHash-SHA256 8448b5ff7fac8b65dd9e5056a8a4b3e4230b7b602f46e24f1667821a64a90e6e 2026-04-14
FileHash-SHA256 d5a3321b215d2b141de7ebe24398cf43320a2016e4f20d079ddf7015ceb069a8 2026-04-14
FileHash-SHA256 dad0ca56b3fe2aeb1f7908765f279db5fc33392caf4849c573a5d63bf7e15604 2026-04-14