Malicious PDF — malware analysis report

Static analysis result for SHA-256 8909eb5d8a11c9b7…

MALICIOUS

PDF

11.6 KB Created: 2009-02-19 14:45:49 -02:00 Authoring application: Writer (via OpenOffice.org 3.0)
MD5: 2b4ca54f28381b02c2da5561ee909b79 SHA-1: 89cd817f9c319095042533658169a270ace9ec6a SHA-256: 8909eb5d8a11c9b754fbf8d58b5bd01cc4117398b11eea158c709d902e891dd1
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The presence of eval() and String.fromCharCode suggests obfuscated JavaScript code designed to perform malicious actions. ClamAV detection as 'Pdf.Exploit.Agent-35541' further confirms its malicious nature. The primary attack vector appears to be exploiting a PDF vulnerability to execute this script, which likely leads to the download and execution of a secondary payload.

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
be8f902ec1347804d101756446ed7a8bb417e3ab9aa965e329de62cb1fedbe1a
pdf-javascript-stream PDF /JS object 27 at offset 0x21C1 15637 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).