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

Static analysis result for SHA-256 7e4d0f230ee4c455…

MALICIOUS

Office (OLE) / .XLSX

1.17 MB
MD5: b2195f0bcacb996c1ab33e9a61fa51c0 SHA-1: 0dc080356fd53c168c596c9ccd7515e66cb0acd2 SHA-256: 7e4d0f230ee4c455559aab72c90e47be45e1c82f83869515a72dcc5313d2c28a
140 Risk Score

Malware Insights

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

The sample is an OOXML document encrypted with a default password, indicating an attempt to obscure its malicious nature. It contains an Equation Editor OLE object, a known vector for exploiting vulnerabilities. The presence of an 'Ole10Native' stream within the Equation Editor object suggests it carries a secondary payload, likely executed upon opening the document.

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.