Malicious PDF — malware analysis report

Static analysis result for SHA-256 e5978f98aa73555c…

MALICIOUS

PDF

3.9 KB
MD5: 6716409ba430591b2c557485962d0c3e SHA-1: 459efbc9771ed63c7d6064751398f0988a991a59 SHA-256: e5978f98aa73555c52edfa140daf1911887edf7491c78d8b4768685c98b4e1ce
112 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1566.002 Spearphishing Attachment

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The presence of ASCIIHexDecode and ASCII85Decode filters, along with ClamAV detection as Pdf.Exploit.Agent-36178, strongly suggests exploitation of a PDF vulnerability to execute malicious JavaScript. The exact nature of the JavaScript payload could not be determined due to obfuscation, but it is likely designed to download and execute a second-stage payload.

Heuristics 6

  • ClamAV: Pdf.Exploit.Agent-36178 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36178
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • ASCII85Decode filter (with exploit indicators) low PDF_FILTER_85
    ASCII85 encoding filter present alongside exploit delivery indicators — uncommon outside of obfuscation