Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a78d8aea8625620…

MALICIOUS

PDF

375.0 KB
MD5: a580ce8c55dd6bbcbc1d77612a860a0c SHA-1: b894e6c005b616ab3a7b62b3e79e58f95245c129 SHA-256: 0a78d8aea8625620040a67ea05b796fe4af997a955697ccba6884b161dabe173
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file is a PDF containing embedded JavaScript, flagged by multiple heuristics and a machine learning classifier as malicious. The JavaScript appears to be obfuscated and attempts to decode a Base64 string, likely to download and execute a second-stage payload. The ClamAV detection 'Pdf.Exploit.Agent-36175' further confirms its malicious nature, indicating it's an exploit targeting PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 5

  • ClamAV: Pdf.Exploit.Agent-36175 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36175
  • 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.
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
5d18f262dcfc8bd73b686d6974a0ba32485751e5d3dfa39e27b522a256c56b4a
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 127736 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36175
Obfuscation or payload: unlikely