Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1fca25843a85afd…

MALICIOUS

PDF

17.4 KB Created: 2009-08-11 07:43:27 Authoring application: mfT3S4cAKzU (via X6tUw0NL)
MD5: 1039dda912548db56aa71b61585ceaf8 SHA-1: f95b4546d4c55771ab222a938e3516422f39078f SHA-256: d1fca25843a85afd394456b8d0d4ab2f872ae6342dc637d65fa4a735ecd9bb0d
336 Risk Score

Malware Insights

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

This PDF file contains obfuscated JavaScript that exploits multiple Adobe Reader vulnerabilities, specifically CVE-2007-5659 (Collab.collectEmailInfo) and CVE-2008-2992 (util.printf). The JavaScript is heavily encoded and uses a custom Base64 decoder, indicating an attempt to evade detection. The primary goal appears to be the execution of a second-stage payload, as suggested by the exploit kit detection and the ML classifier's high confidence score. No document body text was available for analysis, but the embedded scripts and exploit detections strongly indicate a malicious intent to compromise the user's system.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • Multi-CVE Adobe Reader JavaScript exploit kit critical PDF_ADOBE_READER_MULTI_CVE_JS_KIT
    One recovered JavaScript stage contains multiple version-gated Adobe Reader exploit branches. This is stronger evidence than independent API keywords: the PDF is selecting old Reader vulnerabilities by viewer version and running heap-sprayed Acrobat JavaScript exploit paths.
  • ClamAV: Js.Trojan.Obfus-48 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Js.Trojan.Obfus-48
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (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.
  • 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.
  • 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_obj0007_000.js
57e4fb06b9e6406873f373d43b9cd631b80fd19b4715a16bad4191a7142645f9
pdf-javascript-stream PDF /JS object 7 at offset 0x23F 16455 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
custom_b64_stage_000.js
2b4cf28a403615caad4efec5075a95ee85b040e6dee78b3e6dc1451bfdf201cd
deobfuscated-js custom Base64 decoded JavaScript layer 3 (PDF /JS object 7) at offset 0x117D 4567 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).