Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c8038826e21f9a…

MALICIOUS

PDF

16.3 KB Authoring application: sli
MD5: 38907a0890ad08a2e3056477375f1e42 SHA-1: 575b39632705b4f484599b5895b675593f61417a SHA-256: 31c8038826e21f9a5c6bf3d83f28de8d149957101a5ff5cf2cdeef063030d0b3
418 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript, identified as a character-table eval stager. This stager is designed to exploit multiple Adobe Reader vulnerabilities including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The primary function appears to be the execution of a second-stage payload, as indicated by ClamAV detections of 'Pdf.Exploit.Dropped-91' and 'Pdf.Exploit.Agent-36839'.

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)
  • ClamAV: Pdf.Exploit.Dropped-91 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Dropped-91
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Large character-table JavaScript eval stager high PDF_JS_LARGE_CHAR_TABLE_EVAL_STAGER
    PDF JavaScript contains a large numeric index array, a short character table, an indirect eval sink, and a long loop that reconstructs a hidden stage. This is an exploit-kit staging technique even when the recovered first stage is still encoded.
  • 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
8f948435d533deb68a7e17e76cdc86a8fe6583fff06b00ae240f6463d8a58ef4
pdf-javascript-stream PDF /JS object 76 at offset 0x3FE 15468 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36839
Obfuscation or payload: unlikely
array_char_table_stage_000.js
6f3be2291153a334388b09a0142a2b57e92a26d53bd16dfd52613d8a4ca22c43
deobfuscated-js array character-table decoded JavaScript at offset 0x42A 3866 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).