Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b80518a97c0089…

MALICIOUS

PDF

61.2 KB
MD5: 35fa5af4f3caa30a8864234f1fc18181 SHA-1: 6e8aeb26d77e103b45d53422d2cdb76717d1cd49 SHA-256: 21b80518a97c0089ca5a542d76188bb1930c515f3475112ea8eecdf1b5bbce65
358 Risk Score

Malware Insights

The PDF file contains embedded JavaScript that utilizes character-table indexing to deobfuscate and evaluate malicious code. This technique is used to exploit several known vulnerabilities in older versions of Adobe Reader, including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The deobfuscated JavaScript is likely responsible for downloading and executing a secondary payload, as indicated by the ClamAV detection of Win.Trojan.Agent-36331.

Heuristics 9

  • 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)
  • ClamAV: Win.Trojan.Agent-36331 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Agent-36331
  • Character-table JavaScript eval stager high PDF_JS_CHAR_TABLE_EVAL_STAGER
    PDF JavaScript reconstructs an exploit stage by indexing into a small character table, appending hundreds of one-character fragments, joining the array, and evaluating the result. This static fallback fires only after the bounded decoder recovers an exploit-like stage, so it catches this obfuscation even when no single CVE API signature is available.
  • 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.
  • 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_obj0076_000.js
5184cbdd631cb3cebe03848283594797a27e7f2380a65e3faf99f0600a14cda3
pdf-javascript-stream PDF /JS object 76 at offset 0x2D4 54002 bytes
char_table_stage_000.js
cb30d86dff79006245d0141c14d6414fb3f4ad3bf53a14809fb9ba90e8dfaf63
deobfuscated-js char-table indexed JavaScript (PDF /JS object 76) at offset 0x324 3864 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).