Malicious PDF — malware analysis report

Static analysis result for SHA-256 c498b8f2e2ac655f…

MALICIOUS

PDF

9.0 KB Created: 2009-11-06 19:43:43 Authoring application: PDF Library 5.6.9 (via PDF Library 10.10.9)
MD5: 3ec8122eeec63c68634fe159e3544344 SHA-1: c5f19e3dab531e545c8d30b52c41ef4eb3bc3c27 SHA-256: c498b8f2e2ac655f9bc779509bd0e372fa2da642b37c9d5868d4b6ec87608253
278 Risk Score

Malware Insights

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

The PDF exploits multiple known vulnerabilities in Adobe Reader, specifically targeting Collab.getIcon, Collab.collectEmailInfo, and util.printf functions. Static analysis indicates that the embedded JavaScript, particularly the deobfuscated 'legacy_pdfkit_stage_000.js', is designed to download and execute a secondary payload, as evidenced by ClamAV detection 'Js.Exploit.Shellcode-18'. The exploit leverages obfuscated JavaScript and specific PDF filters to achieve its objective.

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
ec821b79bf0cca957c260efe9ba304aaf8ca777d5428910424e0e215eaed8a36
pdf-javascript-stream PDF /JS object 7 at offset 0x268 38574 bytes
legacy_pdfkit_stage_000.js
34c047a5abc7d22cf6211101690cbb8d6bda60fc3fb386a4de852cfdb48d9349
deobfuscated-js numeric array subtract-key decoded JavaScript at offset 0x268 9964 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).