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

Static analysis result for SHA-256 d597ccda6ba602a4…

MALICIOUS

Office (OLE) / .XLSX

180.0 KB
MD5: 3cf84f63359e0b82a4fc7077707abe31 SHA-1: 949c31cdb0d5a9af00db58cf16a5921316c17e5f SHA-256: d597ccda6ba602a4594847d871106a6fc15135ef32247bd4de26af3b24f4b8c2
120 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File

The critical heuristic firing indicates exploitation of CVE-2017-0199 via an OLE object, which is designed to load a remote resource. The sample is an encrypted OOXML file, further suggesting it's an exploit carrier. The embedded OLE object points to a URL that likely hosts the second-stage payload. The encryption and exploit carrier heuristics confirm the malicious intent.

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/69rR
  • 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.