Malicious PDF — malware analysis report

Static analysis result for SHA-256 408ddf56a81dca7c…

MALICIOUS

PDF

118.5 KB
MD5: 864a90502ec990771ce27eb62f681447 SHA-1: ef7e00110f0c0d3b181969cbbe5772e5df65d8a1 SHA-256: 408ddf56a81dca7ca310f00efbb3cf3549e0ee4c4e46b49b824455c8debb174f
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The file is a PDF containing obfuscated JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', 'PDF_EVAL', and 'PDF_JS_LARGE_COMMENT_PADDED_EVAL'. The ClamAV detection 'Pdf.Exploit.Agent-36086' strongly suggests it's a malicious exploit. The embedded JavaScript, particularly the 'eval()' call and the large comment-padded stager, is designed to execute arbitrary code, likely downloading and running a second-stage payload. The document body is unreadable, but the technical indicators point to a common exploit delivery mechanism.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36086 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36086
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Large comment-padded JavaScript eval stager high PDF_JS_LARGE_COMMENT_PADDED_EVAL
    PDF JavaScript contains a very large stream padded with long random-looking block comments around String.fromCharCode and eval. This is an exploit-kit obfuscation shape used to bury a decoder and recovered stage inside noise, not normal PDF form automation.
  • 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)
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
68d909b3009ea27dfd8e4b8fba0321b45a0f8c3851c9e5708389918f4bf5f481
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627020 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 42 long base64-like blob(s).