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

Static analysis result for SHA-256 489c9c338fa0e3c0…

MALICIOUS

Office (OLE) / .XLSX

62.5 KB
MD5: 48cae91c5041c14f0681558149cc2ea8 SHA-1: b64cdb854f3dbe93c4af9532b8a3e87ce1afea3d SHA-256: 489c9c338fa0e3c05bdc1ee738d4dfd5c00838603203ff7dce8ad83dc6eaef8a
120 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File

The critical heuristic firing indicates the exploitation of CVE-2017-0199, a known vulnerability for remote code execution. This is further supported by the presence of an encrypted OOXML exploit carrier and the extraction of a URL that likely serves as the initial payload source. The document is encrypted with a default password, a common tactic to hinder static analysis.

Heuristics 3

  • OLE2Link / URL Moniker → remote loader — CVE-2017-0199 critical CVE likely CVE_2017_0199
    Document contains an embedded OLE link object whose URL Moniker points to a remote URL. When the host file is opened, Office follows the link, downloads the URL, and processes the response based on its Content-Type (HTA -> mshta.exe, RTF → Word, etc.) — the documented CVE-2017-0199 primitive. The URL extension is not a reliable filter; servers can return different payloads to Office's user agent.
    URL https://pnut.co/69q4
  • 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.