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

Static analysis result for SHA-256 afe6510974f5df42…

MALICIOUS

Office (OLE) / .XLSX

1.14 MB
MD5: 4c25706e23ee6fb16f494c6363604b1f SHA-1: 959eac523ea052851a1f90e12ab5152bb662c988 SHA-256: afe6510974f5df4297d20315f7c22da1040e6e13efff31409e347a3de287c964
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1559.001 Component Object Model T1204.002 Malicious File: User Execution

The file is an encrypted Excel spreadsheet that utilizes embedded OLE objects, with a high-confidence detection of the Equation Editor vulnerability. The presence of an Ole10Native stream within the Equation Editor object, coupled with an anomalous header and size discrepancy, strongly suggests it's designed to carry and execute a secondary payload. The encryption with a default password further indicates an attempt to evade static analysis.

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.