Malicious PDF — malware analysis report

Static analysis result for SHA-256 19a2e535aa305fd3…

MALICIOUS

PDF

116.4 KB Created: 2009-07-29 09:08:53 +08:00 Authoring application: WPS Office 个人版 (via PDFlib 7.0.3 (C++/Win32))
MD5: 41bf352ad5d991245148f86b4a8ba0c1 SHA-1: 4f25ea6c029ec239443ea345a2d49fa1a90f0f29 SHA-256: 19a2e535aa305fd36a3ca0a1c155911899afe5d895e70b0a4093f6d863a85142
336 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file contains embedded JavaScript that leverages the Collab.getIcon method to exploit CVE-2009-0927. The JavaScript is heavily obfuscated using String.fromCharCode and unescape functions, indicating an attempt to hide its malicious payload. The primary function of the script is to download and execute a secondary payload, as suggested by the critical heuristic firings related to exploit clusters and ClamAV detections.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 9

  • 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. (matched in decompressed stream)
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • ClamAV: Pdf.Exploit.Agent-20409 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-20409
  • 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.
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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.
  • 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_obj0029_000.js
f254da164e9b164ee2aa3ec290268ae9ce75afac618daa9b3c017ab5aa1beaa7
pdf-javascript-stream PDF /JS object 29 at offset 0x1C346 6268 bytes
Detection
ClamAV: Pdf.Exploit.Agent-35646
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
font_00_sfnt_off00000a82.bin
7a4b69cdf7e60403689092ac272be4ca59a66aa5c37aa89f7781b389d981bd8d
pdf-font-stream PDF embedded font (sfnt) at offset 0xA82 202952 bytes
font_01_sfnt_off00008e6a.bin
0936461790959a8a07650c8f012878814262935f11c8ec9ca55ae94f9e1ebf76
pdf-font-stream PDF embedded font (sfnt) at offset 0x8E6A 21688 bytes