Malicious PDF — malware analysis report

Static analysis result for SHA-256 83279fdd5b52ae51…

MALICIOUS

PDF

4.5 KB
MD5: 22f137c698d28efcc5b074141e778151 SHA-1: a7f5e6b646512a5279b91ea7b5c44405a3e8ca00 SHA-256: 83279fdd5b52ae5105752dc68d6334ddb2bae7b0277aaff82493906ee3e20b23
128 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.002 Malicious Link

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. A critical finding is the CVE-2008-2992 exploit, which leverages `util.printf` to decode and execute JavaScript. This script is likely designed to download and execute a second-stage payload, as suggested by the `eval()` call and the presence of deobfuscated JavaScript files. The attack pattern is consistent with exploiting PDF vulnerabilities to deliver malware.

Heuristics 6

  • 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)
  • 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
83e8fbece71400283da3f52804c3e28cad5409021cfe04922af2dc9233e35d61
pdf-javascript-stream PDF /JS object 5 at offset 0x107 24839 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
906b53c64d0ff057f1fb7f9810d7dc649370b9125991b6885249187dee3cba70
deobfuscated-js numeric char-code string decoded JavaScript at offset 0x115 7305 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).