Malicious PDF — malware analysis report

Static analysis result for SHA-256 da0eca07671fa426…

MALICIOUS

PDF

15.7 KB
MD5: 16cd27314195290727aecbd3b7c29461 SHA-1: 11a755f4ccd802ac0766e971b3ce72e38615bea5 SHA-256: da0eca07671fa426f365008a0b7daf4e69b1e6ce11fba4b4db65c0a457c5c252
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.007 JavaScript

The PDF contains embedded JavaScript, with high-confidence heuristics indicating the use of eval() and a large comment-padded JavaScript eval stager. ClamAV detected this file as 'Pdf.Exploit.Agent-36086'. The embedded JavaScript is heavily obfuscated, but the presence of eval() and fromCharCode suggests it is designed to download and execute a second-stage payload. The exact nature of the payload or its destination could not be determined due to the obfuscation.

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
4edf944376ab4842d9f5bc6530f38e71b67069251d4375dc126cec35949ca23b
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425730 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
d6825177f9b179450f7bc1690ae52f53f1b846389a8da6fa4ac8db18f5aafdab
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 614 long base64-like blob(s).