Malicious PDF — malware analysis report

Static analysis result for SHA-256 922b5519ddeee049…

MALICIOUS

PDF

2.3 KB
MD5: 488406bf73f7b0200afae8a75f160db2 SHA-1: 9b23a417a705ac322d1fad57ee4372cc4a6e8414 SHA-256: 922b5519ddeee04937270a7c2ea3dc933f158bfb184633bb2dce4c246eb6a184
286 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript that leverages the CVE-2009-4324 vulnerability (media.newPlayer). The JavaScript uses eval() and unescape() functions, indicating obfuscation, and String.fromCharCode is also present. Static analysis detected an extracted artifact with ClamAV signatures indicating exploit shellcode. The primary attack vector appears to be exploiting a PDF reader vulnerability to download and execute a secondary payload.

Heuristics 9

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-36082 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36082
  • 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)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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_obj111611_000.js
772da696bdb365f3f1eb4ea6af881baad391be62f3591b19f2f9827fcc4c9b53
pdf-javascript-stream PDF /JS object 111611 at offset 0x828 479 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
2ce2bbf9c0bbd1cb8787d79b23ffc04c10baabdfade4f7a8b78f3a1d62d803dd
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2433 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).