PDF malware analysis — malicious · fd21bc31c19c8850

MALICIOUS

PDF

15.7 KB

MD5: 8a457108bc43c5149694b8babfa5f02c SHA-1: 85762b6529a75b91be9cc7be0183094a9a34f086 SHA-256: fd21bc31c19c885040e83db80b6cbacc51ba743bfc62b7304f42ddafd4aea078

166 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 JavaScript/JScript T1204.002 Malicious File T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript that utilizes eval() and String.fromCharCode, indicating obfuscated code execution. A heuristic specifically flags a 'Large comment-padded JavaScript eval stager'. This suggests the script's primary purpose is to download and execute a secondary payload, as indicated by the ClamAV detection signature 'Pdf.Exploit.Agent-36086'. The lack of readable document body text prevents a more specific determination of the lure, but the technical indicators strongly point to a malicious exploit delivery.

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.

Filename	Kind	Source	Size
`javascript_obj0006_000.js` `69c89523c8ce640594a0d1f0ce13b23b3844350dd05f711f91e58dba53d62410`	pdf-javascript-stream	PDF /JS object 6 at offset 0x143	425771 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).

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