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

Static analysis result for SHA-256 29e2599419f70c7e…

MALICIOUS

Office (OLE) / .XLSX

1.25 MB
MD5: 4d78e31905fa4ca34a8228128e158114 SHA-1: 07cc2f9baefc7ea8922be45cabb7eda764f6e3a4 SHA-256: 29e2599419f70c7ee9cfec59bf38d60256a4a6c819d4e7705799ba1cc53094c7
140 Risk Score

Malware Insights

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

The sample is an OOXML file encrypted with a default password, indicating an attempt to hide its malicious nature. It contains multiple embedded OLE objects, specifically identified as Equation Editor objects, which are known exploit carriers. One of these objects exhibits an anomaly where the Ole10Native stream appears to carry a payload, strongly suggesting exploitation of a vulnerability within the Equation Editor.

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.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Default-encrypted OOXML embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is exploit-shaped Equation/OLE payload evidence.
  • 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.