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

Static analysis result for SHA-256 024ea196549edcb0…

MALICIOUS

Office (OLE) / .XLSX

475.3 KB
MD5: 067d9cc300062805cf3e3a8c7f165c57 SHA-1: 01a12e3f8f1a07baec31217138bb6c2513e28ad3 SHA-256: 024ea196549edcb09049db635bfbff96a955cc949c72106fb36bd25e574b7706
180 Risk Score

Malware Insights

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

The sample is a password-encrypted OOXML file that contains an embedded Equation Editor OLE object, a common carrier for exploits. The encryption and malformed CFB FAT suggest an attempt to hinder analysis and likely conceal malicious code. This combination strongly indicates an exploit delivery mechanism, likely via spearphishing attachment, targeting a vulnerability such as CVE-2017-11882.

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.
  • Encrypted Office package with CFB FAT corruption critical OLE_ENCRYPTED_AND_MALFORMED
    Encrypted-package shape co-occurs with FAT-chain corruption — the documented combined evasion form.
  • 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.