Xls.Downloader.94c25b356b5a6cac-9978798-0 — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 5c3a3771b7f55454…

MALICIOUS

Office (OLE) / .XLSX

110.0 KB First seen: 2022-08-02
MD5: 2b72b3688e43ced6b792c6fb9b65a466 SHA-1: 235ced26da34fd90df7d2b59b8915fff41f2cb2c SHA-256: 5c3a3771b7f5545469fa1f34bb19a4e41e5401b774c2c7ec10e3301400cf6027
202 Risk Score

Malware Insights

Xls.Downloader.94c25b356b5a6cac-9978798-0 · confidence 95%

MITRE ATT&CK
T1204.002 Malicious File T1059.001 PowerShell T1059.003 Windows Command Shell

The sample is a password-encrypted Office document that leverages the CVE-2017-0199 vulnerability. This vulnerability allows the embedded OLE object to load a remote resource from the URL 'https://khaurl.com/H4Md1?&interloper=odd&cocktail=piquant&therapist=delightful&luck=loving&league=slimy&pavilion=utter&farmer=spotless&term'. This indicates the file acts as a downloader for a secondary malicious payload.

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: Xls.Downloader.94c25b356b5a6cac-9978798-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.94c25b356b5a6cac-9978798-0
  • 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 https://khaurl.com/H4Md1?&interloper=odd&cocktail=piquant&therapist=delightful&luck=loving&league=slimy&pavilion=utter&farmer=spotless&term