Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4077968b6ac3260…

MALICIOUS

PDF

11.6 KB
MD5: 0df4b78cf61e7293d16a2979acf45021 SHA-1: c099065dcde8586e78006fd01170ef99652f60f5 SHA-256: b4077968b6ac3260034b865502a1fa970bbf72691eb65bc178e8076bdeab59cd
146 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that leverages the CVE-2007-5659 vulnerability, specifically using the Collab.collectEmailInfo method. The JavaScript is heavily obfuscated but appears to be designed to download and execute a secondary payload. The presence of multiple JavaScript streams and the critical ClamAV detection further support its malicious nature. The attack pattern is consistent with exploit-based PDF documents.

Heuristics 6

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-36079 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36079
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
ef8bdac794684ae9cd4eb7091d80e1c5ca478c06c639d72d01626c1f7ce78b6d
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 578 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
736d650694c321d873a1bed031a7b6ce2fc8b116b165867aad41b3479c93ed7f
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 12165 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
3a7326b968d6fbb3ba835889fbbbbe5607670d307c5ee6f35f7b581aa9d8963b
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 5004 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).