Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d7b3e8d61e703e9…

MALICIOUS

PDF

4.5 KB Created: ert Authoring application: Adobe (via asd)
MD5: 8cc7c7fc4e46d5734fc6cd5ab59e68a0 SHA-1: 3c99c7e882b836b9e3654377814512e69e8b088e SHA-256: 8d7b3e8d61e703e9d71da30d85cb2835682c05fb8bd50d407bee9625e69e9e3f
258 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Script: JavaScript Execution T1204.002 Malicious File: User Execution: Malicious File

The PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-4324, CVE-2009-0927, and CVE-2007-5659 through embedded JavaScript. The deobfuscated JavaScript, identified as legacy_pdfkit_stage_000.js, was flagged by ClamAV as Js.Exploit.Shellcode-18, suggesting it contains shellcode. This indicates the PDF is designed to exploit these vulnerabilities to execute malicious JavaScript, which in turn likely downloads and executes a further payload.

Heuristics 7

  • 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)
  • 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.
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
legacy_pdfkit_stage_000.js
eb66ea7c2fba0cd9663910de9dc943d08f2aebe5e3aaf9d88d698de6c50b3146
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1B7 6872 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 12 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).