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

Static analysis result for SHA-256 7945dda20d783f46…

MALICIOUS

Office (OLE) / .XLSX

93.5 KB First seen: 2022-04-27
MD5: e815dd99ef729490d4283405659b916d SHA-1: a2abb7a1366ae236494f5421987abfd0a25d92a4 SHA-256: 7945dda20d783f46a64b222935b834693cd44bf4b77aadc180d205da0e39fa22
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The file is an encrypted Office document, identified as an exploit carrier due to the presence of an Equation Editor OLE object. The high entropy and anomalous native stream in the Equation Editor object strongly suggest exploitation of CVE-2018-0798. This vulnerability allows for arbitrary code execution, likely to download and execute a second-stage 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)).
  • 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.