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

Static analysis result for SHA-256 12529c7d367852ae…

MALICIOUS

Office (OLE) / .XLSX

344.0 KB First seen: 2022-04-12
MD5: b7058c408fb42ab00c2f3ba55c84beb4 SHA-1: 9aadb17719b12f2ec348b1ae73159a77f03c6b38 SHA-256: 12529c7d367852ae7f0617a54c4b1b6952c1ecb05b1e156a63568f0f43746464
120 Risk Score

Malware Insights

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

The sample is a password-encrypted Excel file containing an Equation Editor OLE object, a known carrier for exploits. This strongly suggests it's designed to exploit a vulnerability in the Equation Editor to achieve arbitrary code execution upon opening. The default encryption further indicates a common exploit delivery technique.

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.
  • 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.