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

Static analysis result for SHA-256 f08c0dfbc93cae4d…

MALICIOUS

Office (OLE) / .XLSX

592.0 KB
MD5: e884ff7cf6d4d5f68a6c73f71874c31e SHA-1: 08fc8137451cb9b53eec149f306f1b30bd167c8a SHA-256: f08c0dfbc93cae4d8306af7e7d0eb56eb01ca5ac86a3c9a0eeb216d76a77ce47
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.002 Phishing: Spearphishing Attachment

The sample is an encrypted OOXML file containing embedded OLE objects, specifically identified as an Equation Editor exploit carrier. High-entropy anomalous native streams within the Equation Editor object strongly indicate the presence of a known exploit, likely CVE-2018-0798. This exploit is designed to execute arbitrary code upon opening, facilitating the delivery of a malicious 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.
  • 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.
  • 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.