Malicious PDF — malware analysis report

Static analysis result for SHA-256 20fb98dbe4868af4…

MALICIOUS

PDF

60.7 KB
MD5: 55d6c1426ba370a75c25b34ef0d89efe SHA-1: 4f6cdc9fcc4510af2f4b4cea6e060e0275ad50cb SHA-256: 20fb98dbe4868af4201d89889f7a66ff80de162451c802efa1fee733246200f2
396 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1059.007 JavaScript

The PDF file contains embedded JavaScript that utilizes character-table indexing and eval functions to deobfuscate and execute malicious code. Critical heuristics indicate exploitation of CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992, all of which are known Adobe Reader vulnerabilities. The deobfuscated JavaScript is likely a stager designed to download and execute a secondary payload, as indicated by the 'eval_char_append_stage_000.js' artifact.

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: Pdf.Exploit.Agent-36310 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36310
  • 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.
  • Suspicious extracted artifact high 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.
  • 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0076_000.js
10b3e7eef45a55235d5750bde3428aa8c287f18b6af1a60fd7891f062ef78788
pdf-javascript-stream PDF /JS object 76 at offset 0x2D4 53538 bytes
eval_char_append_stage_000.js
87e6113380e29a44ab7924968fae3366aacb49454267a34b674a89e9d339ac7d
deobfuscated-js eval character-table append decoded JavaScript at offset 0x300 3846 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).