Malicious PDF — malware analysis report

Static analysis result for SHA-256 77cd7b228ddbe901…

MALICIOUS

PDF

180.2 KB
MD5: b7afb5e083321a74aaaf5579ddb0359e SHA-1: 3876eccc27bd7d4c69254b4364e07c066d92bc08 SHA-256: 77cd7b228ddbe90131faed728ac76110fdb30fc7bd3616d0105e3dbe0198da45
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 within the PDF document. These exploits leverage embedded JavaScript, as confirmed by the PDF_JAVASCRIPT and PDF_JS firings. The extracted JavaScript artifacts, including 'legacy_pdfkit_stage_000.js', are indicative of a downloader or exploit loader. ClamAV detections on both the main file and extracted artifacts further support its malicious nature. The primary attack vector appears to be exploiting PDF reader vulnerabilities to execute arbitrary code.

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
6c638fd51a4d04960f7fc485bb7bd653512bf7ea1734588383e33aab4ddb596f
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
f4d7b9f969b944f6e13417f68cc0af5f257b83378fd66a8da8cfbb738e53c818
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xC9A 20111 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).