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

Static analysis result for SHA-256 d0e842c7c371c73f…

MALICIOUS

Office (OLE) / .XLSX

223.5 KB First seen: 2022-05-20
MD5: 02b4919e879f843e5634b26396f037bc SHA-1: d059bd390de212341fbb1471b180729811b8ed79 SHA-256: d0e842c7c371c73f8f3ed2c4630066a67c461027d63f6aeca9dc59a316f62a0c
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an encrypted Office document containing an embedded Equation Editor OLE object. Heuristics indicate this object is likely an exploit carrier for CVE-2018-0798, a vulnerability in Equation Editor. This exploit allows for arbitrary code execution when the document is opened. No document body or script content was extractable due to encryption, limiting further analysis of the payload.

Heuristics 5

  • 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 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.