PDF malware analysis — malicious · 37cf2f38cffd0b07

MALICIOUS

PDF

15.7 KB

MD5: 83dca247261e62854bd0fd736f6ef2c3 SHA-1: 45356c6ae7e81335043f25634a64d2b572cff2a5 SHA-256: 37cf2f38cffd0b077710501a3c9db557e033623c0d4510f1cfddb39a2e222a6a

166 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1071.001 Web Protocols

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_EVAL'. The 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' heuristic suggests a stager designed to execute obfuscated JavaScript. This script likely downloads and executes a second-stage payload, as suggested by the ClamAV detection 'Pdf.Exploit.Agent-36086'. The document body is heavily obfuscated and unreadable, providing no direct clues to the lure.

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.

Filename	Kind	Source	Size
`javascript_obj0006_000.js` `3cd891b952fbbc89b6164a845ba8be40e46c8f6d40a69284014ccd8c90bbd898`	pdf-javascript-stream	PDF /JS object 6 at offset 0x143	425812 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).
`legacy_pdfkit_stage_000.js` `8b5ead1a81fad7c9c596bf665988b4f6329016c2ab64cc9638fa575cb2b74b2e`	deobfuscated-js	double percent-decoded annotation JavaScript at offset 0x143	262144 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 693 long base64-like blob(s).

Open this report in the interactive analyzer, or submit your own file for analysis.