Malicious PDF — malware analysis report

Static analysis result for SHA-256 de993ff274c411ec…

MALICIOUS

PDF

118.6 KB
MD5: 4cbe9796cf7330e4ac6a898b6b59be46 SHA-1: 59ec8c53f85fe70aa671fae3ac513fe53758fdb6 SHA-256: de993ff274c411ec44ac2a1ae0613a449fe88eb04ce4dd4a97a7b428129482da
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, including a large comment-padded eval stager. This JavaScript is obfuscated and uses eval() and String.fromCharCode(), indicating an attempt to hide malicious code execution. The ClamAV detection 'Pdf.Exploit.Agent-36086' strongly suggests this is a known exploit. The primary function appears to be the execution of a secondary payload, likely downloaded from an external source, though no specific URLs were extracted.

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
d25802649587f520aea040161a279eed5e6f1281e1995c2e97d2a8c73bb1c20f
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626196 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).