Malicious PDF — malware analysis report

Static analysis result for SHA-256 afb1642f596d5156…

MALICIOUS

PDF

15.7 KB
MD5: 9bfb0b9f66c8dc7b812ce06c5d1f368b SHA-1: e7734150da9d1b351b00ec1c4a3f9e0c431c8538 SHA-256: afb1642f596d515680fc79817bc1c2e2084883f86dd4076c2a9e06c1037c0704
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious JavaScript

The PDF file contains embedded JavaScript, including a large comment-padded eval stager. This indicates the file is designed to execute malicious code upon opening. The presence of `eval()` and `String.fromCharCode` within the JavaScript stream strongly suggests obfuscation and dynamic code execution, typical of exploit delivery. ClamAV detection as 'Pdf.Exploit.Agent-36086' further confirms its malicious nature.

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.

FilenameKindSourceSize
javascript_obj0006_000.js
052473a4d3a4b77ace32d1a5ed18336fa2b698ed76f61d66a48c43cbcf784b7b
pdf-javascript-stream PDF /JS object 6 at offset 0x143 426181 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).