Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b9c565909aefb4f…

MALICIOUS

PDF

125.9 KB
MD5: 4893d9c392aa5f5bb4709f4bdc262f0f SHA-1: 00633ead7761088229e0cb8a2d32bb49e0348e53 SHA-256: 3b9c565909aefb4fd1e5078f6afeba87b8d7509ec96649b556a031514581fd16
318 Risk Score

Malware Insights

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

The sample is a PDF file that contains embedded JavaScript, exploiting known vulnerabilities such as CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The embedded JavaScript, particularly the deobfuscated script 'legacy_pdfkit_stage_000.js', is designed to execute arbitrary code. This script likely downloads and executes a second-stage payload, as indicated by the ClamAV detections on extracted artifacts.

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: Win.Trojan.Agent-36169 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Agent-36169
  • 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
6ffe2d3db060a1b5782b8ab61408160e5d352b6d4c30e6d0650121145a288e8b
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 1903 bytes
Detection
ClamAV: Win.Trojan.Agent-36169
Obfuscation or payload: unlikely
legacy_pdfkit_stage_000.js
dbe28dce7d8ac64c36d42cc7f3cdeac5f74f6434b34431f812aec5e09e68982d
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x98A 8412 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).