Malicious PDF — malware analysis report

Static analysis result for SHA-256 375340ac9e3cdb54…

MALICIOUS

PDF

118.7 KB
MD5: 5837c6dd0ba58775cd1bec8d8647c5a7 SHA-1: 0328dce1fba84ed590da745bbb3258a09bcf1623 SHA-256: 375340ac9e3cdb54c4bf7d683590f7bba6416407a4b05c05d235906cede447a9
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains embedded JavaScript, with high-confidence heuristics indicating the use of eval() and a large comment-padded eval stager. ClamAV also detected this as Pdf.Exploit.Agent-36086. The obfuscated JavaScript streams suggest the execution of a second-stage payload, but the exact nature and destination could not be determined due to the heavy 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
7f337a523cdaaaf6aa2a7f96f2c4799820ceb7ce3e0fcf312d3c655d0381e085
pdf-javascript-stream PDF /JS object 6 at offset 0x143 628481 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
f3aaab0999ce1b0cd1d05b81b855a702f2d1740906cab61de93825df5bb7159c
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 586 long base64-like blob(s).