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

Static analysis result for SHA-256 aa610173afefde94…

MALICIOUS

Office (OLE) / .XLSX

197.0 KB
MD5: c3524b3b21dae7ebf0d9ed6b6c10f5ec SHA-1: 72ebb819703693105a86d206a119f88821c84b54 SHA-256: aa610173afefde94cf914948a54de1d63b71475cdd0d9bb18e6f01d67a2076a9
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file identified as an exploit carrier. It contains an Equation Editor OLE object that is anomalous and indicative of CVE-2018-0798. This suggests the file is designed to exploit this vulnerability for client-side execution, likely delivered as an attachment.

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.