Malicious PDF — malware analysis report

Static analysis result for SHA-256 7198a7d1fd43b1ee…

MALICIOUS

PDF

4.3 KB
MD5: 7e3d5b55a03bf6d57df26a23de4d6047 SHA-1: 50e1d80dbdd27d5cee047cf431ed5559df7e4f48 SHA-256: 7198a7d1fd43b1eef481779c377f55c4982bd95f729a01c409f76a5b32f5e463
216 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file contains embedded JavaScript that leverages the CVE-2008-2992 vulnerability in Adobe Reader. The script uses String.fromCharCode and eval() to deobfuscate and execute exploit code. The deobfuscated JavaScript appears to be designed to download and execute a secondary payload, indicated by the ML classifier's high confidence and the presence of exploit cluster heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 7

  • 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)
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • 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. (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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
850d2bb178abef03fea403208f43cb80daee79a71bb84e2257988531a4449366
pdf-javascript-stream PDF /JS object 5 at offset 0x107 22759 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
numeric_charcode_stage_000.js
37df34f504f6ae5d5b62f992cc2346ddc304b8e87bb162c28600c5a2d1893617
deobfuscated-js numeric char-code string decoded JavaScript at offset 0x115 6676 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).