Malicious PDF — malware analysis report

Static analysis result for SHA-256 b784adb69e013f8d…

MALICIOUS

PDF

7.3 KB
MD5: a03bddac96895c2a7f82a0337d0879a0 SHA-1: 18fc4cac5253840ffb08af78474793534e3232cb SHA-256: b784adb69e013f8da69399b0cfd30a6005f0901b250760bdca6e2b65dfe672f9
266 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.001 User Execution: Malicious Link T1204.002 User Execution: Malicious File

The sample is a PDF file that leverages multiple critical vulnerabilities (CVE-2009-4324, CVE-2009-0927, CVE-2007-5659) to execute embedded JavaScript. The JavaScript is XOR-decoded and obfuscated, but analysis indicates it likely downloads and executes a second-stage payload, as evidenced by the ClamAV signature 'Js.Exploit.Shellcode-18'. The extracted JavaScript files confirm the presence of obfuscated scripts designed for exploitation.

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
33706c52516e8506e5b92a48cf5a345a1871a5cb252deff833fb13290df97f75
pdf-javascript-stream PDF /JS object 39 at offset 0x16F 28079 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
5b9713b24ca2f3ad63839b771c3e3c53bdc066d7fc4958eaf906da5deae096f6
deobfuscated-js numeric array XOR decoded JavaScript at offset 0x16F 5344 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
1498a25280444fc9e04889a0622422b714ff4dc559d344fcc836b48a36a0ed2e
deobfuscated-js numPages XOR decoded JavaScript at offset 0x16F 5344 bytes