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

Static analysis result for SHA-256 9733156bcc612dc5…

MALICIOUS

Office (OLE) / .XLSX

344.0 KB First seen: 2022-04-12
MD5: 7cf52a50283878529ce4e0b4558eff1c SHA-1: 0571c18a7c098e6468b9ffb858d42b7cd2c395c3 SHA-256: 9733156bcc612dc5b921301201061834a74536a43467095afad926f3a62cc074
120 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1559.001 Component Object Model Hijacking

The file is an encrypted Office document containing an Equation Editor OLE object, a known exploit carrier. The heuristics indicate the use of the Equation Editor vulnerability, which is commonly used to deliver second-stage payloads. No specific family could be identified due to the lack of script content or network indicators.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Default-encrypted OOXML embedded OLE object xl/embeddings/oleObject1.bin contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • 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 document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007, AES)).
  • 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.