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

Static analysis result for SHA-256 9be4c2db7fb366da…

MALICIOUS

Office (OLE) / .XLSX

79.5 KB First seen: 2022-06-21
MD5: 0a132a014d8ecb8821874f40eeb498c2 SHA-1: ffa69b001b1e9ed0ceaba6bfdf1affa70899460e SHA-256: 9be4c2db7fb366da843e9e4009a048975de66bba520aadf67679853864fda8c0
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious File T1059 Command and Scripting Interpreter T1059.003 Windows Command Shell

The sample is a password-encrypted Office document containing an embedded Equation Editor OLE object. High-confidence heuristics indicate this object is designed to exploit CVE-2018-0798, a vulnerability in Microsoft Equation Editor. This exploit likely leads to the execution of a second-stage payload. No document body or scripts were extractable due to encryption, limiting further analysis of the payload's specific intent.

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)).
  • 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.