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

Static analysis result for SHA-256 fabb4bd1643660e4…

MALICIOUS

Office (OLE) / .XLSX

1.29 MB
MD5: 82113034a5e21545dd7970eaec81743c SHA-1: fede3552ddae2f248bb54fed1dd020a33f84319a SHA-256: fabb4bd1643660e4e0207c06f3462851fd39612a29755e1aa55dda6f9760819c
140 Risk Score

Malware Insights

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

The sample is an OOXML file encrypted with a default password, indicating it's designed to hide its malicious content. It contains an Equation Editor OLE object, which is a known vector for exploiting vulnerabilities. The anomaly detected in the Ole10Native stream suggests it carries a payload, likely intended for execution upon user interaction.

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.