Malicious PDF — malware analysis report

Static analysis result for SHA-256 629819642d6ef13f…

MALICIOUS

PDF

4.4 KB
MD5: dc35db628ee319b8dbefcb6d606dedf9 SHA-1: 377c9635ae65f5c4dbc98af1b7839ddba78e5f65 SHA-256: 629819642d6ef13f141bfbb41b78a47ed8b11dc287e2f8ae6bea1a7bed4484c7
216 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript that utilizes the `eval()` function and `String.fromCharCode()` to construct and execute exploit code targeting CVE-2008-2992. The deobfuscated JavaScript appears to be part of a multi-stage exploit chain designed to download and run a malicious payload. The high confidence is due to the critical heuristic firings and the clear presence of exploit code.

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
6137536ef954452309116c0b760de503698fdd41633ecf98191d5c9ec8d4e0b6
pdf-javascript-stream PDF /JS object 5 at offset 0x107 23264 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
6d7913cc8406284af4d27120b36c13e460969fea0c62a413701ba43393183bc8
deobfuscated-js numeric char-code string decoded JavaScript at offset 0x115 6859 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).