PULSE NAME
FormBook Malware Uses Phishing, DLL Side-Loading, JavaScript
WHITE AlienVault 2026-04-22 Modified: 2026-04-22
6
IOCs
LOW VOLUME
Two distinct phishing campaigns have been identified targeting companies in Greece, Spain, Slovenia, Bosnia and Central American countries to deliver FormBook data-stealing malware. The first campaign uses RAR attachments containing legitimate executables like Sandboxie ImBox.exe, TikTok desktop, Adobe PDF Preview Handler, and XZ Utils, exploiting DLL side-loading with malicious DLL files. The second campaign deploys heavily obfuscated JavaScript that drops encrypted PNG files, uses PowerShell with Base64 encoding, and leverages a custom .NET loader called Mandark to inject the payload into RegAsm process. Both campaigns deliver the same FormBook executable that employs advanced evasion by manually mapping ntdll.dll in memory to bypass user-mode monitoring and perform direct syscalls, enabling credential theft and data collection from browsers while avoiding detection mechanisms.
Indicators of Compromise (6)
All FileHash-MD5 FileHash-SHA1 FileHash-SHA256
TYPEINDICATORDESCRIPTIONCREATED
FileHash-MD5 872116260461fe63dd8664dbfbc7efa0 2026-04-22
FileHash-MD5 8d79722188d998327dd7edf9924bffe2 2026-04-22
FileHash-MD5 9601283e3153779f5a7e845365fdd87d 2026-04-22
FileHash-MD5 ab0d213d4df3de06bbd2db524fb73282 2026-04-22
FileHash-SHA1 3d1eaf0777aac4c76ff406b9ecf82af7d045b8f3 2026-04-22
FileHash-SHA256 4140d26ecad2fd8a3ea326ee49f5dd8bda3696e0d1ae6e756db6d61d70bf3af4 2026-04-22