Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b8d4f5886ddb9d5…

MALICIOUS

PDF

1.9 KB
MD5: 43c532f845a2df873f0addc50140b203 SHA-1: aaf30f2c95f8137339db0e8895f674acbaa31786 SHA-256: 3b8d4f5886ddb9d528d44b197b0e0502e86dc91f5cca2c4c18edaeb1f98f304b
278 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript that utilizes `eval()` and `unescape()` functions, indicative of obfuscation. The critical heuristic `CVE_2009_4324` specifically points to the exploitation of a known PDF vulnerability via JavaScript. The presence of ClamAV detections for `Pdf.Exploit.Agent-35930` and `Js.Exploit.Shellcode-18` further confirms its malicious nature. The embedded JavaScript is likely designed to download and execute a secondary payload, a common technique for initial access.

Heuristics 8

  • 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-35930 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35930
  • 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.
  • 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
f23e505f155bfa9b9f356fa9fddf8d7fcafcc37fc2df3878e575e72c00c819d4
pdf-javascript-stream PDF /JS object 111611 at offset 0x6B2 697 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
2532b2228c7b74dc00ea793620efd604c4d538915bf9e6639f50bebaaeb181d3
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).