Malicious PDF — malware analysis report

Static analysis result for SHA-256 248582574443c151…

MALICIOUS

PDF

12.0 KB Created: 2009-11-25 19:44:76 Authoring application: PDF Library 1.9.9 (via PDF Library 8.4.4)
MD5: 8780e4be875a84fbed6dc2f7a89cfe6d SHA-1: 0c4edffa455603a2c38ff5abc37ae0717876fb6e SHA-256: 248582574443c151f3853bb621ea5e36a2d7961d476871e0167c5bf0e8cc9caa
278 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1204.002 Malicious File

The PDF leverages multiple critical vulnerabilities in Adobe Reader, specifically targeting Collab.getIcon, Collab.collectEmailInfo, and util.printf functions. Static analysis indicates that these exploits are used to execute obfuscated JavaScript, which was further deobfuscated into 'legacy_pdfkit_stage_000.js'. This script is flagged by ClamAV as 'Js.Exploit.Shellcode-18', suggesting it likely downloads and executes a second-stage payload. The exploit chain points to a classic PDF-based exploit kit delivery mechanism.

Heuristics 8

  • 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)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (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.
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
47a2b85757afa843edc285127b037c5f68c50ab81a5c34261326c931534983e1
pdf-javascript-stream PDF /JS object 7 at offset 0x268 37415 bytes
legacy_pdfkit_stage_000.js
5dc77c0f60c885225b2e62bc4394086ecb120bd87bf30d2b6602d9d5a08d0dd4
deobfuscated-js numeric array subtract-key decoded JavaScript at offset 0x268 9874 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).