Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8a9b3aa09c569f0…

MALICIOUS

PDF

180.5 KB
MD5: c4bff0f42ca502cbffffe579e078fc5b SHA-1: 3f11cc6a0a4cb4ebd8570ccbf913d37974e7f443 SHA-256: d8a9b3aa09c569f017782cba8bf84741af7dee6382d7c647720159ef4698d862
318 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, which exploits multiple known vulnerabilities including CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are heavily obfuscated but indicate the execution of shellcode and potential download of further payloads. ClamAV detections further confirm its malicious nature, identifying it as 'Pdf.Exploit.Agent-36114' and related extracted artifacts as 'Js.Exploit.Shellcode-18' and 'Pdf.Exploit.Agent-36307'. The script's intent 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: 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
d491eed953d71d5d46f2739ae6ef190b101601c2b5f16527186fd3401a6a7ae1
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
daf0d2b63bbb62d653531db02129af66fcaeb6182c2e0b9af8be4d4577ab2acf
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xC9A 20141 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).