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

Static analysis result for SHA-256 fb62d2ef00dc39a9…

MALICIOUS

Office (OLE) / .XLSX

1.29 MB
MD5: 3552282fd0c7e231361d44cc918c3ba0 SHA-1: d2bdb4b0ba264c5ae600f6243a124dd02340db23 SHA-256: fb62d2ef00dc39a9d08e81cbccb945f956a5906e35b3ed94b08ff13f90def46e
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file is a password-protected Excel spreadsheet identified as malicious. It contains an Equation Editor OLE object which is known to be a carrier for exploits. The heuristics indicate that this OLE object contains a payload-like Ole10Native stream, suggesting it's designed to deliver a secondary exploit or payload. The presence of embedded OLE objects points towards an exploit delivery mechanism.

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.
  • 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.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Default-encrypted OOXML embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is exploit-shaped Equation/OLE payload evidence.
  • Office document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007+, AES-128)).
  • 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.