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

Static analysis result for SHA-256 53cb7a3ffb08c981…

MALICIOUS

Office (OLE) / .XLSX

1.35 MB
MD5: ca7fcfefb7df4968331cfc4f47702851 SHA-1: 10b920058589bac4f8d97453128c0b11c992c7fb SHA-256: 53cb7a3ffb08c981ec11ea164f6cb47daf3c7e1ee2616f1f57d01c95d64e24b9
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file is an encrypted OOXML document that contains an Equation Editor OLE object. This object appears to carry a payload, indicating it's likely used to exploit a vulnerability in the Equation Editor component to deliver a malicious payload. No specific family could be identified, and no external IOCs were extracted.

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.