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

Static analysis result for SHA-256 6a0a14fea572ac8e…

MALICIOUS

Office (OLE) / .XLSX

93.5 KB First seen: 2022-04-29
MD5: d9da666e1b1d654546fd876f25208302 SHA-1: 2fe267bc5c2898567acd7efedd35a45c17d2c6dc SHA-256: 6a0a14fea572ac8e09a2165d0dc723d61727459673648a338a4b5056c8a4090c
160 Risk Score

Malware Insights

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

The sample is a password-encrypted Office document containing an Equation Editor OLE object. Heuristics indicate it is likely an exploit carrier for CVE-2018-0798, which allows for arbitrary code execution when the Equation Editor is loaded. The document's encrypted nature and the presence of an exploit object strongly suggest it is intended to be delivered as a malicious attachment.

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.