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

Static analysis result for SHA-256 c8e1fc6b4a2e2f61…

MALICIOUS

Office (OLE) / .XLSX

83.5 KB First seen: 2022-08-18
MD5: 7c6b1d2d883dd18f8aff3342f62671d9 SHA-1: d2d07a6d1b9907591509d572bc6403e4001f655d SHA-256: c8e1fc6b4a2e2f614895cd7c7b8cc8d8d96ae6120a6a7b1c315bf43fbf7a5ac1
202 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.001 PowerShell

The file is an encrypted Office document that leverages the CVE-2017-0199 vulnerability. This vulnerability allows the document to act as a remote loader, fetching and executing a secondary payload from the embedded URL http://23.95.34.121/invc/https_b/www.doc. The ClamAV detection further confirms its malicious nature as a downloader.

Heuristics 6

  • 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.
  • ClamAV: Doc.Downloader.Formbook-bc97c1e0c33c3c93-9951465-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Formbook-bc97c1e0c33c3c93-9951465-0
  • 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 document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007, AES)).
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://23.95.34.121/invc/https_b/www.doc

Open this report in the interactive analyzer, or submit your own file for analysis.