Malicious PDF — malware analysis report

Static analysis result for SHA-256 c97cb2e964887343…

MALICIOUS

PDF

11.8 KB
MD5: c120058a53c33a8ecf50efbc07adc145 SHA-1: d8a2d78f5649e48d65b29b67b4d46c7f0f64df28 SHA-256: c97cb2e9648873439ed2d651ff4c3c8c4ceef65b15ff5c2200f34dcfe691611e
146 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, which is flagged as malicious by ClamAV (Pdf.Exploit.Agent-36079). The critical heuristic CVE_2007_5659 indicates the exploitation of a known PDF vulnerability (Collab.collectEmailInfo) to execute JavaScript. This JavaScript is likely responsible for downloading and executing a second-stage payload, although the exact mechanism is obfuscated. The presence of multiple JavaScript streams and the critical heuristic strongly suggest an exploit attempt.

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
efad9dff780c45235ceccb10fe9409e68011d82f93179620e2941158a81ae71c
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 12107 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
4c5a366784a6595c09cad3cb7a718c4c2bd70ed509eac2806e44fac662dccc8d
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 5000 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).