Malicious Office (OLE) / .XLSX — malware analysis report

Static analysis result for SHA-256 85b1f90df077def5…

MALICIOUS

Office (OLE) / .XLSX

32.5 KB
MD5: 6c861e0f424eb28fdb00559cfdb7826e SHA-1: a9c467ef0a0bdb8ab527c7fbcc76bc7fdd98d962 SHA-256: 85b1f90df077def5606d189203a26ee2f70436567ea3187637ec8cc77a7c4920
60 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1137.006 Office Application Build

The OOXML file is encrypted with a default password, a common technique to hinder static analysis and disguise malicious content. Heuristics indicate the presence of an embedded OLE object, suggesting it acts as a carrier for a secondary exploit or payload. Without a document body or scripts, the exact nature of the attack is unclear, but the encryption and embedded object strongly point to a malicious delivery mechanism.

Heuristics 2

  • Default-encrypted OOXML exploit carrier layout high OOXML_ENCRYPTED_EXPLOIT_CARRIER_SHAPE
    Default-password encrypted OOXML package contains embedded OLE object parts and additional activation/decoy parts. This layout is common in malicious Excel exploit delivery and requires inspecting the decrypted package.
  • Office OOXML encrypted with default VelvetSweatshop password medium OFFICE_DEFAULT_PASSWORD_ENCRYPTED_OOXML
    OLE EncryptedPackage decrypts with Excel's built-in VelvetSweatshop password. Office opens this transparently, and malware uses it to hide OOXML exploit parts from scanners that only inspect the outer OLE container.