Malicious PDF — malware analysis report

Static analysis result for SHA-256 e5556bbdb55a6ca0…

MALICIOUS

PDF

15.7 KB
MD5: 54c1ff9bba09fe2e34eeae05a8926079 SHA-1: 9d818268047146a15e75fc30640f063026b04029 SHA-256: e5556bbdb55a6ca044c15b0b06f8c2da97a38855ddf8467ec9a8288f3929550a
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious JavaScript

The file is a PDF containing embedded JavaScript, as indicated by multiple PDF-specific heuristics including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_FROMCHARCODE'. A critical heuristic 'PDF_EVAL' and 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' further suggest the JavaScript is obfuscated and designed to be executed. ClamAV detection as 'Pdf.Exploit.Agent-36086' confirms its malicious nature. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload.

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
b20f075045124ff1d99d1759b4b79800aa41728aff4be36da6e439e584aee4d9
pdf-javascript-stream PDF /JS object 6 at offset 0x143 424571 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).