Malicious PDF — malware analysis report

Static analysis result for SHA-256 406de90a3da311cc…

MALICIOUS

PDF

118.6 KB
MD5: 62e00f3607fa6292f21d2a47443666bf SHA-1: 8853e7d2eab8641cd724c5f6de7110e2c12c570f SHA-256: 406de90a3da311ccedb888049971a3490f9529cdf750bc69f88704d00aa96398
166 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, with high-confidence heuristics indicating the use of eval() and a large comment-padded JavaScript eval stager. ClamAV also detected this file as 'Pdf.Exploit.Agent-36086'. The presence of JavaScript and the eval() calls strongly suggest the intent to download and execute a second-stage payload. The document body was not sufficiently readable to determine a specific lure.

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
5e73b9e2a2819c303ffb6aafde45f2fc9426615157f08f1d08618a01bc353de9
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627060 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
6b0a98649b24c777f4091dcb65b53b0faa84ce2d7d398f2651e0cea763936068
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 630 long base64-like blob(s).