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

Static analysis result for SHA-256 f0201869c74fe4db…

MALICIOUS

Office (OLE) / .XLSX

1.44 MB
MD5: 1d5642afb0456e0161dde56e23b37836 SHA-1: 675997ba543ab32f0c47b7f8a1988cfa17e3ccb9 SHA-256: f0201869c74fe4dba4aac66549e332d9bf27ab2347ea8a6e7525110f0b927b0f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1566 Phishing T1204.002 Malicious File: User Execution

The sample is an OOXML file that is encrypted with a default password and contains an Equation Editor OLE object. This object is known to be used as an exploit carrier, specifically for vulnerabilities like CVE-2017-11882. The presence of an 'Ole10Native' stream within the Equation Editor object indicates it likely carries a secondary payload, although the specific nature of that payload cannot be determined from the provided evidence.

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.