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

Static analysis result for SHA-256 9853da661450f9b9…

MALICIOUS

Office (OLE) / .XLSX

2.37 MB
MD5: 3b5f7a2a0429e796040aa5bc3763a8fe SHA-1: c049ac5a44d034995a55bd5f49aece9631c69c1f SHA-256: 9853da661450f9b9a4c06dc952bc70d7cdd8e80cf7e9f8189f2d15682bd88434
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.001 Malicious Link: Malicious Link T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1059 Command and Scripting Interpreter

The file is an Office document encrypted with a default password, indicating it's likely a carrier for malicious content. High-severity heuristics indicate the presence of an Equation Editor OLE object that is anomalous and carries a payload. This strongly suggests exploitation of a vulnerability within the Equation Editor, such as CVE-2018-0798, to execute arbitrary code. No document body or scripts were extractable, but the exploit carrier structure is sufficient for a high-confidence assessment.

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.
  • CVE-2018-0798 — anomalous Equation Editor native stream high CVE likely CVE_2018_0798_EQUATION_NATIVE_ANOMALY
    Default-encrypted OOXML contains embedded Equation Editor data with anomalous native stream bytes consistent with a CVE-2018-0798-style exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like.
  • 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.