Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ec04daa8dd161d6…

MALICIOUS

PDF

12.0 KB
MD5: 6cc5a191b4fa49cb4da1d649dc220011 SHA-1: 90f6866b964fb11b238c7a606e3274af91b7aa5d SHA-256: 8ec04daa8dd161d6f7867123e6c5dcd881d9a4257120465f2b0df7e37a70de6f
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. This JavaScript is heavily obfuscated but appears designed to download and execute a secondary payload. The presence of multiple deobfuscated JavaScript files and the ClamAV detection further support its malicious nature. The attack pattern is consistent with exploiting PDF reader vulnerabilities to initiate a download chain.

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
65f55b7855b75c15cc8b687f2e2e5025027237c66a70ff6aee1f8e316c826251
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 12443 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
3f8ffe21ab408bad900993cb3260f44d74d685fd6bee0b8539f8696c4249e216
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 5137 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).