Malicious PDF — malware analysis report

Static analysis result for SHA-256 240009504780d1cd…

MALICIOUS

PDF

15.7 KB
MD5: 85b6485d54254aeb6554269f31159f88 SHA-1: 0162c6895d427bc90392f73b6cd3e00377321b57 SHA-256: 240009504780d1cd8fb6d2cdc51e24a9e7ecf91a48d3843a2a197d2ca77f325c
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1071.001 Web Protocols

This PDF file contains embedded JavaScript that utilizes eval() and String.fromCharCode(), indicating an attempt to obfuscate malicious code. The 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' heuristic firing strongly suggests a stager designed to download and execute a secondary payload. The ClamAV detection 'Pdf.Exploit.Agent-36086' further confirms its malicious nature, pointing towards a known exploit targeting PDF viewers.

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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
b852e88437a3178ccee391e5bfc7f29f83eb6c6b82b7caec199e434fa7bddc01
pdf-javascript-stream PDF /JS object 6 at offset 0x143 423999 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).
stream_001_off00003b54.bin
37ed64b0c9ec67edd4bad24ab832f302f498eee7940febb92c03aa47ea113f30
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x3B54 300 bytes