Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5386b2e600b40fd…

MALICIOUS

PDF

180.1 KB
MD5: 9b5c7a0e36a60c9efcaf4f5b2b302d05 SHA-1: 89c523fa93b6fb9c119a88436516d0fa23e13b1f SHA-256: c5386b2e600b40fd47b40a78fb4bc1f1ef9cacc8fa6f4c4187318bfbe57b2ea7
318 Risk Score

Malware Insights

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

Multiple critical heuristics indicate the exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992 through embedded JavaScript. The ClamAV detections on the main file and extracted artifacts further confirm its malicious nature. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are likely responsible for downloading and executing a second-stage payload, a common technique for PDF-based malware.

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: Pdf.Exploit.Agent-36114 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36114
  • 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
93177825c85ecfcafe9f2bd2f7f9954e4c10881e6afd8ad415914cc9628f8166
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 2687 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36307
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_000.js
0dcb18cb157f78e7af1ea302bc032ff9e3d731cdc751f71e07d84f1ee6b698de
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xC9A 20099 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).