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

Static analysis result for SHA-256 fab74e6e08763b9b…

MALICIOUS

Office (OLE) / .XLSX

1.28 MB
MD5: 1b530dc1394b4a84d8f68c76f89eb08d SHA-1: c47ab452385aecd0d9582081a44fc446298183ed SHA-256: fab74e6e08763b9bdb907253b587b607d73742cf989cd12332ed0b92abce7e55
140 Risk Score

Malware Insights

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

The sample is an OOXML file that is encrypted with a default password and contains an embedded Equation Editor OLE object. This object is known to be used as a carrier for exploits, specifically targeting vulnerabilities within the Equation Editor component. The presence of an 'Ole10Native' stream anomaly further suggests it's designed to deliver a secondary payload.

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.