Malicious PDF — malware analysis report

Static analysis result for SHA-256 f121a9eda6423a2c…

MALICIOUS

PDF

17.3 KB Created: 2009-07-25 11:52:23 Authoring application: lB4UbQLl (via kG2ML3AZt3Cb8)
MD5: db74aef6ab77c6238cde5f26aa916e00 SHA-1: 16f6501cab7f903d1b1846c4967062ed1bdeb6c6 SHA-256: f121a9eda6423a2c05f749da398474a29524bf8aaa45366bae2faa856976d66e
336 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript that exploits multiple Adobe Reader vulnerabilities, specifically CVE-2007-5659 and CVE-2008-2992. The JavaScript is heavily obfuscated and uses custom Base64 decoding to unpack further layers, ultimately leading to the execution of a malicious payload. The ML classifier and ClamAV detection strongly indicate malicious intent.

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
8fa35a797670d63f3681e84d6a6fa2c05ccd5b9f2f3a7c2d53406d75fe46486f
pdf-javascript-stream PDF /JS object 7 at offset 0x23F 16332 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
1efe8be658226a399f9b1a9ffa75ccaab579a34298874d1597a253e04c15bb40
deobfuscated-js custom Base64 decoded JavaScript layer 3 (PDF /JS object 7) at offset 0x114D 4563 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).