Malicious PDF — malware analysis report

Static analysis result for SHA-256 1acd690e0114e4ae…

MALICIOUS

PDF

118.5 KB
MD5: 9191ff6ef7be81a125913ab33f1b6610 SHA-1: ee3c84d37646c65e78630ac7b04e2594500783d4 SHA-256: 1acd690e0114e4aec8a581e8015a27160259864b16e77ec7d005f0666b6cc801
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Script: JavaScript Execution T1204.002 Malicious File: User Execution: Malicious File

The PDF contains embedded JavaScript, including a large comment-padded eval stager, indicating an attempt to execute malicious code. The presence of `eval()` and `String.fromCharCode` further supports this. ClamAV detection as 'Pdf.Exploit.Agent-36086' confirms its malicious nature, likely involving an exploit. The obfuscated nature of the JavaScript and the lack of readable document body text prevent a more specific determination of the payload's intent.

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
8c49eaea10ac7e8072acb296a0edf09754b74f42060d077a1832f6d2a8b35781
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626837 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
2fc1ebbe099baf0ae9862b309e8ce1f7b44a52a074766910c5d543d2bda8fb24
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 648 long base64-like blob(s).