Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2d8f3ad6f756ba5…

MALICIOUS

PDF

60.7 KB
MD5: 876dfd93fbbca5747c5d6df76f08260a SHA-1: 58599da33726cf874963db92c5e173bc25fac190 SHA-256: b2d8f3ad6f756ba5f96d312b55607d58d304604263f414a9db3af4bbdc10f3a1
358 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes character-table indexing to reconstruct and evaluate malicious code. This technique is used to exploit several known vulnerabilities including CVE-2009-4324 (media.newPlayer), CVE-2009-0927 (Collab.getIcon), CVE-2007-5659 (Collab.collectEmailInfo), and CVE-2008-2992 (util.printf). The deobfuscated JavaScript likely serves as a stager to download and execute a secondary payload, indicated by the 'eval_char_append_stage_000.js' filename and the critical heuristic firings.

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.
  • 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
b9e8cc07bca7a4e0db43ffc9a118b7c9dc1146e57a033ef0fbc8ee4d78cb9c8e
pdf-javascript-stream PDF /JS object 76 at offset 0x2D4 53536 bytes
eval_char_append_stage_000.js
0db9f7dccbc26c99c208dc429b4bed57507b218b4f4cc1008f1892fe37be058b
deobfuscated-js eval character-table append decoded JavaScript at offset 0x300 3852 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).