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

Static analysis result for SHA-256 acecc129924c19e0…

MALICIOUS

Office (OLE) / .XLSX

20.3 KB First seen: 2022-03-18
MD5: 88dd2b2f773976649ede0d7196b24951 SHA-1: 3bc6652c992ce253954a612acc97ca29a741616d SHA-256: acecc129924c19e01fe98272d382c556843ce3640ea5ab449049697457164070
202 Risk Score

Malware Insights

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

The sample is a password-encrypted OOXML document identified as an exploit carrier. It specifically leverages CVE-2017-0199, which is a known vulnerability for remote code execution via OLE2Link and URL Moniker. The embedded URL 'https://2l.lv/24' is highly suspicious and likely serves as the distribution point for a second-stage payload. The document's encrypted nature and the critical heuristic firings strongly indicate its malicious intent 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.
  • Encrypted Office package with CFB FAT corruption critical OLE_ENCRYPTED_AND_MALFORMED
    Encrypted-package shape co-occurs with FAT-chain corruption — the documented combined evasion form.
  • 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://2l.lv/24