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

Static analysis result for SHA-256 1dec762da4aa7fc3…

MALICIOUS

Office (OLE) / .XLSX

478.0 KB
MD5: b5f9c5223a6cbf2328ddd01835ae8280 SHA-1: d292f759ac92e5beafb0aefda4b2d3a70d2611ec SHA-256: 1dec762da4aa7fc39d095862cfe7b7b323dc799c3e57a2cc1a37d3efdce2e674
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an encrypted OOXML file that contains an Equation Editor OLE object, a common carrier for exploits. The encryption with a default password further suggests malicious intent. While no specific payload or delivery mechanism is directly visible, the presence of the Equation Editor OLE object strongly indicates an attempt to exploit a known vulnerability, likely delivered via a spearphishing attachment.

Heuristics 3

  • 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.
  • 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.