Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecca816336d998f5…

MALICIOUS

PDF

11.6 KB Created: 2009-02-19 14:45:49 -02:00 Authoring application: Writer (via OpenOffice.org 3.0)
MD5: e4ce02be18327ea18f4f44a55d97f6c8 SHA-1: 36eb36e8d3a91b5af55a4d39262afe1ca629e501 SHA-256: ecca816336d998f559259d50d285bfb50902f459e9a4d38e0554fab2f20c2aa9
196 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Exploit.Agent-35541. Static analysis detected embedded JavaScript with eval() calls and String.fromCharCode usage, indicating obfuscated code execution. The PDF also contains a launch action, suggesting it's designed to trigger an exploit. The embedded JavaScript stream, named javascript_obj0027_000.js, is likely responsible for downloading and executing a secondary payload, which is a common attack pattern for this type of exploit.

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
e7816394bdda3fca045d85c931c0953ff11af1d00bf06c3bac2cb1dca3d83e6b
pdf-javascript-stream PDF /JS object 27 at offset 0x21C1 15638 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).