Malicious PDF — malware analysis report

Static analysis result for SHA-256 969663f93633c3f3…

MALICIOUS

PDF

6.7 KB
MD5: 1475bee42b11db4dd9edf50b674b067a SHA-1: 387157b8492d4898792dae2dc6c307cadd871bdb SHA-256: 969663f93633c3f3e3dd33b448e3d7436cf5a1923e174fdb8288d51aba995b98
266 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1071.001 Web Protocols

The PDF file contains embedded JavaScript that exploits multiple known vulnerabilities including CVE-2009-4324, CVE-2009-0927, and CVE-2007-5659. Static analysis detected obfuscated JavaScript streams, and heuristic analysis identified these as malicious, specifically noting the use of String.fromCharCode and the exploitation of PDF vulnerabilities. The extracted JavaScript is likely responsible for downloading and executing a second-stage payload, as indicated by the ClamAV detection of 'Js.Exploit.Shellcode-18'. The specific vulnerabilities targeted suggest an older exploit kit or a custom exploit leveraging these known weaknesses.

Heuristics 8

  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0039_000.js
01ff97b894ed5eaa73f893f09448057eb97e8a254b7796755073c3ed7ac81378
pdf-javascript-stream PDF /JS object 39 at offset 0x16F 20606 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
120d086d0b76d7e18b4806f4b762b312618aad12b1f2f30254bf572fb1708769
deobfuscated-js numeric array XOR decoded JavaScript at offset 0x16F 5416 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
8e76b89962a3ff1175434556061a1f846e3fe1c67c8a2b2bd1d1bb8cf58a4001
deobfuscated-js numPages XOR decoded JavaScript at offset 0x16F 5416 bytes