Malicious PDF — malware analysis report

Static analysis result for SHA-256 b0f0c433989de80e…

MALICIOUS

PDF

9.4 KB
MD5: e8cad803d0298a7481eb1e7275be79d3 SHA-1: 6ec5ae0e873dc8e0ce557f6557cb5a40b02b65f2 SHA-256: b0f0c433989de80e8ca778dee3271c93a4d6d3557c2fa7ca6cdd12da1a1a1e69
88 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, specifically triggering the CVE-2007-5659 vulnerability via the `collab.collectEmailInfo()` function. This JavaScript is heavily obfuscated but appears designed to download and execute a second-stage payload. The presence of multiple deobfuscated JavaScript files further supports this. The attack pattern is consistent with exploiting known PDF vulnerabilities to deliver further malware.

Heuristics 5

  • 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)
  • 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_obj0005_000.js
f048286b2dfe205330e162117bc9e2e9406092389e25aa91660890d79cb205b6
pdf-javascript-stream PDF /JS object 5 at offset 0x10E 916 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
7a590a04ea87350e84c3856974289b971d37449302c9c2940b4de6ef81f0d52b
deobfuscated-js z-percent hex-pair decoded JavaScript at offset 0x3CE 4919 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
79371305d462f00f2a141b476e1cf8fba05bdb49c15d53c9a49ff740e927b262
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x3CE 11601 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).