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

Static analysis result for SHA-256 899f3826ad1308ac…

MALICIOUS

Office (OLE) / .XLSX

148.5 KB First seen: 2022-08-25
MD5: a1c157755a3c4ed1ec74f798b013d239 SHA-1: b0e70ad81a57170f8b0fe20a4c6ac38e1d0f8c03 SHA-256: 899f3826ad1308ac3de4a1b4ea86876a102b200f8eac7947812447014bd42e60
120 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking T1204.002 Malicious File

The sample is an encrypted Office document, flagged as a high-confidence exploit carrier. Specifically, it contains an Equation Editor OLE object, a known vector for exploiting vulnerabilities. The encryption prevents direct analysis of the document body, but the presence of the OLE object strongly suggests an attempt to execute arbitrary code.

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-128)).
  • 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.