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

Static analysis result for SHA-256 7d4d2b7824df8eb8…

MALICIOUS

Office (OLE) / .XLSX

1.26 MB
MD5: ab521851f0e5caa83b1f953ae1786df3 SHA-1: 17da88120c3f0e0f873a4c423d2cea8a01c6a8f9 SHA-256: 7d4d2b7824df8eb8ff0c952aecdfd4cb1921bbd5b32a63f0dff164446c95c9bf
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an encrypted OOXML file identified as a malicious exploit carrier. It contains an Equation Editor OLE object, a known vector for exploiting vulnerabilities like CVE-2017-11882. The encryption and the presence of the OLE object strongly suggest it's designed to execute arbitrary code upon opening, likely delivered via spearphishing.

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.
  • Office document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007+, AES-128)).
  • 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.