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

Static analysis result for SHA-256 ccb11db540b028c7…

MALICIOUS

Office (OLE) / .XLSX

1.39 MB
MD5: b82b564fcfaf8d526c8623e4ff68a5a5 SHA-1: 4cf065316d3df3a6c224e10eba32477b8ce46713 SHA-256: ccb11db540b028c7524e40415fed0f21d180db473d738c33097e0d871df5cdc2
140 Risk Score

Malware Insights

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

The sample is an OOXML file encrypted with a default password, indicating an attempt to hide its malicious content. It contains multiple embedded OLE objects, specifically identified as Equation Editor objects, which are known exploit carriers. One of these objects, 'oleObject1.bin', exhibits an anomaly where an 'Ole10Native' stream, typically carrying a payload, is found within the Equation Editor object, strongly suggesting it's used to deliver a secondary exploit or payload.

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.