Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b134fde3b6a479a…

MALICIOUS

PDF

25.3 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode
MD5: 1308ddf864a80ff0a71dfdf81962b9f5 SHA-1: 457b476168b7a58f6cb846f5a499fe38c004b5fe SHA-256: 3b134fde3b6a479a0ceaf32cff5a25196ed01f1732e2714463cd3112b2314cd2
376 Risk Score

Malware Insights

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

This PDF document leverages multiple critical vulnerabilities (CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) through embedded JavaScript. The JavaScript is obfuscated and uses String.fromCharCode, typical of stagers designed to download and execute further malicious content. The ML classifier strongly indicates maliciousness. The primary attack vector appears to be exploiting known vulnerabilities in PDF viewers.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 10

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (identified after JavaScript deobfuscation)
  • 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)
  • PDF metadata arithmetic JavaScript stager high PDF_INFO_ARITHMETIC_JS_STAGER
    PDF metadata hides JavaScript as arithmetic character-code tokens inside document information fields, then a launcher rebuilds it with String.fromCharCode and eval. The decoder is gated on metadata access from the launcher, a large arithmetic token table, and recovered exploit-like JavaScript.
  • PDF metadata JavaScript eval stager high PDF_METADATA_EVAL_STAGER
    PDF JavaScript reads document metadata fields such as title, subject, or producer, decodes character data with parseInt/String.fromCharCode style helpers, and evals the recovered stage. This is a high-signal exploit-kit staging pattern.
  • 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_obj0001_000.js
29ad96865c501bc926668f83f9b94169e9cb11c51118db8189e3f826eebfe39f
pdf-javascript-stream PDF /JS object 1 at offset 0x625C 537 bytes
info_arithmetic_stage_000.js
0d0ffb2d94bf29432767668a5431061b7d6865c0320c2b76f9ed3f50c7f8372e
deobfuscated-js PDF /Info Title arithmetic JavaScript at offset 0x23 3660 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).