Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4fc0ca37b57c386…

MALICIOUS

PDF

132.7 KB
MD5: 809370a7fb05d70ca1269f1d6b3f0ebb SHA-1: 031b7aac50c20851b51fee3f89b6188942f68408 SHA-256: c4fc0ca37b57c38673ed21833653de1e26a74077f0234b9e0bc772aa4bb7b125
258 Risk Score

Malware Insights

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

The PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992 through embedded JavaScript. The extracted JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are heavily obfuscated but detected by ClamAV as 'Js.Exploit.Shellcode-18'. This suggests the script's primary function is to download and execute a secondary malicious payload. The presence of multiple exploit techniques points towards a sophisticated downloader.

Heuristics 7

  • 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.
  • 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_obj0008_000.js
5a660111d0e1c6016332bdab84b82eb547101c835b0b233068419d06398805e7
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 2095 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_000.js
c9aa93a6277d57efbd016799a505a6d254ffbfd15168be96e3010257478c6ad8
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xA4A 14775 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).