Malicious PDF — malware analysis report

Static analysis result for SHA-256 e83b3db4357c9c85…

MALICIOUS

PDF

12.1 KB Created: 2009-12-16 19:43:67 Authoring application: PDF Library 4.1.3 (via PDF Library 10.9.10)
MD5: de07d6249ef3e80b8d528017c30b341e SHA-1: 09f76123b4fd5d9b65515412fa0ca2f5aefd7133 SHA-256: e83b3db4357c9c856dbab55bb1e5a2f5605fda6dcbb699da6a8688a65a3a6a16
278 Risk Score

Malware Insights

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

This PDF document exploits multiple known vulnerabilities including CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. These exploits are triggered by embedded JavaScript, which is further obfuscated and decoded. Static analysis identified a suspicious extracted JavaScript file, 'legacy_pdfkit_stage_000.js', which was detected by ClamAV as 'Js.Exploit.Shellcode-18'. The primary function of the embedded script appears to be downloading and executing a second-stage payload.

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
a4c50b78a026b56903f2d311a9a6e34178df421c759bc88b800d35268436bbcf
pdf-javascript-stream PDF /JS object 7 at offset 0x268 38176 bytes
legacy_pdfkit_stage_000.js
2f2c25948ece0aa6b4bd68d11a102bec9889a20ea48e003442929f0009568088
deobfuscated-js numeric array subtract-key decoded JavaScript at offset 0x268 9880 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).