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

Static analysis result for SHA-256 896c97bf0d43e0d6…

MALICIOUS

Office (OLE) / .XLSX

1.16 MB
MD5: bd0c51bdd40ac45ee0c1a35ac76e6809 SHA-1: 4c736a5861a4915b255964ec37a3c15fc7f4039f SHA-256: 896c97bf0d43e0d64b54e807275ec41cbc689c0706092f6a94cf3d620709a621
140 Risk Score

Malware Insights

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

The sample is an OOXML document that is encrypted with a default password, a common technique for obfuscating malicious content. It contains an embedded Equation Editor OLE object, which is a known vector for exploiting vulnerabilities. The 'OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY' heuristic indicates that this object carries a payload-like stream, suggesting it's designed to execute malicious code upon opening.

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.