Malicious PDF — malware analysis report

Static analysis result for SHA-256 5324649e4f6f5436…

MALICIOUS

PDF

3.7 KB Created: 2008-07-26 19:43:58 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: 837c5516e70d14da7ec22935ae54b0e7 SHA-1: 3f6532d35051e7e0ce468b949d57b69d370d2456 SHA-256: 5324649e4f6f543695cd7143c0fcc3d9c8bcfe3db644e4b2d3e42196498b606f
246 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes the 'util.printf' function, indicating an attempt to exploit the CVE-2008-2992 vulnerability in Adobe Reader. The JavaScript is obfuscated and decodes multiple layers, ultimately aiming to execute a malicious payload. ClamAV signatures confirm this file is malicious, specifically detecting it as Pdf.Exploit.Agent-35551.

Heuristics 8

  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-35551 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35551
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0013_000.js
540b90330355247ed10ff827a4683eaef8d98ecbf7123cb597b6829f11c080fb
pdf-javascript-stream PDF /JS object 13 at offset 0x3CE 5271 bytes
Detection
ClamAV: Pdf.Exploit.Agent-35551
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
custom_b64_stage_000.js
3bc967b97727192e2e45cc786ad0620bdffefe993650221ba1eedec7c4447fa3
deobfuscated-js custom Base64 decoded JavaScript layer 1 (PDF /JS object 13) at offset 0x734 3292 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).