Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8bb77367c54caa8…

MALICIOUS

PDF

11.6 KB Created: 2009-02-19 14:45:49 -02:00 Authoring application: Writer (via OpenOffice.org 3.0)
MD5: e00cfbd554aaccc539ddbe128fdd4e0d SHA-1: a90c1302f08377d358f57f23ec0b4a9bf425c8c6 SHA-256: f8bb77367c54caa8e5861afe7cc98803bec6cc3b38864bff44111fa1457141f3
196 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Exploit.Agent-35541, indicating a known exploit. Heuristics confirm the presence of embedded JavaScript with eval() calls and fromCharCode, suggesting obfuscated code execution. The ML classifier also strongly indicated maliciousness. The primary attack vector appears to be a PDF exploit that leverages JavaScript to likely download and execute a second-stage payload, as indicated by the 'PDF_LAUNCH' and 'PDF_JAVASCRIPT' heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-35541 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35541
  • Launch action high PDF_LAUNCH
    PDF contains a /Launch action with an unresolved or extension-less target — treat as potentially dangerous
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0027_000.js
1902ba79298f264b88c1c4294f73e028ae173807464649e4e2c45a71fc0cde91
pdf-javascript-stream PDF /JS object 27 at offset 0x21C1 15647 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).