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

Static analysis result for SHA-256 358cc99629571c0b…

MALICIOUS

Office (OLE) / .XLSX

196.5 KB
MD5: bd2e55ed9169dbe1605a342bb92803eb SHA-1: 67e0e3f62baedd3c4a74af3173c2b455623a19e3 SHA-256: 358cc99629571c0be144828fb0b97d0c4e1d0b07850793986a4a43d07fdd399d
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model Hijacking

The sample is an encrypted OOXML file that contains an embedded Equation Editor OLE object. Heuristics indicate that this object is anomalous and exploits CVE-2018-0798, a vulnerability in Equation Editor. This suggests the file is designed to execute arbitrary code via the Equation Editor vulnerability.

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.
  • CVE-2018-0798 — anomalous Equation Editor native stream high CVE likely CVE_2018_0798_EQUATION_NATIVE_ANOMALY
    Default-encrypted OOXML contains embedded Equation Editor data with anomalous native stream bytes consistent with a CVE-2018-0798-style exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like.
  • 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 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.