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

Static analysis result for SHA-256 a65c2d416d1be5dd…

MALICIOUS

Office (OLE) / .XLSX

70.8 KB First seen: 2022-06-29
MD5: a08d1d04204a156aa09aa4d4c25b4d14 SHA-1: 0326ab90165dfad6a8684cae19205f97b909546a SHA-256: a65c2d416d1be5dd0aae7781e5f2c28f27f60d2358bd449fd76da284e9001cc7
202 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.001 Command and Scripting Interpreter: PowerShell T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1566.002 Phishing: Spearphishing Link

The sample is an encrypted Office document that exploits CVE-2017-0199 via an embedded OLE object. This exploit is designed to download and execute a second-stage payload from the URL https://golkeeper.github.io@arpix.ch/lBIHs. The document's encrypted nature and the use of a known exploit indicate a malicious intent to compromise the user's system.

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://golkeeper.github.io@arpix.ch/lBIHs