Malicious PDF — malware analysis report

Static analysis result for SHA-256 da95d839c956d4bf…

MALICIOUS

PDF

6.7 KB
MD5: 4b37dc9b87a46e3c49f1af5764d7063a SHA-1: 00450964aa30ac4f8a7906fc62a693cdec493505 SHA-256: da95d839c956d4bfee8d43d15d9ed4ae4b533a685c93256338e0a650ecdd16bc
266 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1059.007 JavaScript

The PDF file contains embedded JavaScript that exploits multiple known vulnerabilities including CVE-2009-4324, CVE-2009-0927, and CVE-2007-5659. The heuristic firings indicate that this JavaScript is XOR-decoded and evaluated by the PDF reader. Analysis of the extracted and deobfuscated JavaScript (legacy_pdfkit_stage_000.js) confirms it is designed to download and execute a second-stage payload, as indicated by the ClamAV detection 'Js.Exploit.Shellcode-18'. The document body is unreadable, but the technical indicators strongly suggest a malicious downloader.

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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0039_000.js
92cb839422e994b3c2031976d36f4a148d37fa8c342817cdfea947ae893d0478
pdf-javascript-stream PDF /JS object 39 at offset 0x16F 22463 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
7b037fa54190e770de0dcf95257be25307cfa7f02f349897a3cc5594440f0b09
deobfuscated-js numeric array XOR decoded JavaScript at offset 0x16F 5326 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).