Malicious PDF — malware analysis report

Static analysis result for SHA-256 a27fa8235e286a10…

MALICIOUS

PDF

83.8 KB
MD5: 43ffd64a87688532376c8b00fc87a8bb SHA-1: 62a77e8f60692ba73c12e1e2d7a4554c1ed4cd34 SHA-256: a27fa8235e286a10ee4c70d364c702175f95d4aeb6dab2436bfe35dceeb5e7cf
396 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes character-table indexing to obfuscate its content, a technique commonly used to evade detection. Critical heuristics indicate exploitation of multiple CVEs (2009-4324, 2009-0927, 2007-5659, 2008-2992) related to JavaScript execution within PDF documents. The deobfuscated JavaScript is identified as a stager, strongly suggesting its purpose is to download and execute a secondary payload, consistent with 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.
  • 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
fb90b2728b8fb1832ec8bba26b219bd63a949f61aebfe7e1b12e6276c6cc64f5
pdf-javascript-stream PDF /JS object 76 at offset 0x2D4 77146 bytes
char_table_stage_000.js
b2a7d13bfed35d02de38cf8121dae305dd4994dcbef2cfa39fc3e88eb3d18e8b
deobfuscated-js char-table indexed JavaScript (PDF /JS object 76) at offset 0x31A 3858 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).