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

Static analysis result for SHA-256 287033316527dcf6…

MALICIOUS

Office (OLE) / .XLSX

1.15 MB
MD5: 6f2134ac1d97032ad1fa925290bc0396 SHA-1: b390c5c76e19e61e35c4377bed7595775868e99c SHA-256: 287033316527dcf69607f5eca8ec03d4e9ffcd3e6cdab437800b144b2cb2acda
140 Risk Score

Malware Insights

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

The sample is an OOXML file encrypted with a default password, indicating a deliberate attempt to obscure its contents. It contains embedded OLE objects, specifically identified as Equation Editor objects, which are frequently used to deliver exploits. The anomaly in the Ole10Native stream further suggests that this object is designed to carry a malicious payload. The combination of these factors strongly points to a weaponized document intended to exploit vulnerabilities.

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.
  • 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 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.