Malicious PDF — malware analysis report

Static analysis result for SHA-256 e71e21817d8da697…

MALICIOUS

PDF

16.0 KB Authoring application: sli
MD5: b09d4083fb1e1518cb473fc3e706a690 SHA-1: 8fd709a47d7c16c901c0b0e2a28d01ad86fd325e SHA-256: e71e21817d8da697f5a50dedf9611047472376cb1aacd35797773759da9ea985
418 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The sample is a PDF file that contains obfuscated JavaScript, identified as a large character-table eval stager. Critical heuristics indicate exploitation of multiple Adobe Reader vulnerabilities including CVE-2009-4324 (media.newPlayer), CVE-2009-0927 (Collab.getIcon), CVE-2007-5659 (Collab.collectEmailInfo), and CVE-2008-2992 (util.printf). These vulnerabilities are used to execute arbitrary code, likely to download and run a second-stage payload. ClamAV detections further confirm its malicious nature.

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
d17f84566ccb39f6e5accbf3609aea3d8bf31679a057b4846b103d669a41138b
pdf-javascript-stream PDF /JS object 76 at offset 0x401 15131 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36839
Obfuscation or payload: unlikely
array_char_table_stage_000.js
f474b5b3a1033dbeeb12ddf825c09a9316c9d0d14449a7c23933ed11491b3546
deobfuscated-js array character-table decoded JavaScript at offset 0x42D 3842 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).