Malicious PDF — malware analysis report

Static analysis result for SHA-256 b86fdac141246b4d…

MALICIOUS

PDF

3.0 KB
MD5: 4bdc4f73875aae2ab913b61d524b9151 SHA-1: 9c54d5ce301fbaceaa176f5002752b3cd208876d SHA-256: b86fdac141246b4df6e5220edaa8d68b1ede9017eab623b765a915502b73c63c
358 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: Malicious File T1059.001 Command and Scripting Interpreter: PowerShell

The PDF file contains multiple critical heuristic firings indicating the exploitation of several CVEs (CVE_2009_4324, CVE_2009_0927, CVE_2007_5659, CVE_2008_2992) related to PDF JavaScript execution. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are likely responsible for downloading and executing a secondary payload, as suggested by the ClamAV detection 'Pdf.Exploit.Agent-35646'. The obfuscated nature of the JavaScript and the use of multiple exploit techniques point towards a downloader or dropper functionality.

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 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.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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_obj0007_000.js
1993359444b9e1f438089c9aa709c1ddfe1eef84ba318c2ffe89322f4b10dd19
pdf-javascript-stream PDF /JS object 7 at offset 0xDB 34838 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
37042c7b2856e32d6f11af4f595766441505a1525b477549b662e00e2760305d
deobfuscated-js split-join delimiter stripped JavaScript at offset 0x109 7502 bytes
Detection
ClamAV: Pdf.Exploit.Agent-35646
Obfuscation or payload: likely
Carved artifact contains 13 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).