Malicious PDF — malware analysis report

Static analysis result for SHA-256 458d706922feaf02…

MALICIOUS

PDF

118.6 KB
MD5: 001699fb92023fc5ae9cb9402aeb2ce3 SHA-1: 5c40c535bf10ad034f4de558c372713b0d02af74 SHA-256: 458d706922feaf02c1ca559b055df664a2c2c59f5064019e0625081054fd6f6f
166 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by ClamAV (Pdf.Exploit.Agent-36086). Static analysis revealed embedded JavaScript with multiple high-severity heuristics, including `PDF_EVAL` and `PDF_JS_LARGE_COMMENT_PADDED_EVAL`. These indicate the script is designed to obfuscate and execute code, likely to exploit vulnerabilities or download further malicious content. The presence of `String.fromCharCode` further supports the obfuscation technique.

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
6f2338f7ba7f35639262a6449c5bd763a42f607c393c583a5c94005dc03991bc
pdf-javascript-stream PDF /JS object 6 at offset 0x143 625991 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).