Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8407c24b66178cb…

MALICIOUS

PDF

118.8 KB
MD5: 95ccd134403b508b4f874eba156a2c49 SHA-1: 8bcd431bfe64cc2681b3586010adf27732ef6e21 SHA-256: d8407c24b66178cbe0bdfb28b78599d76017460187f08a0e2adc8cea8885327b
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Script Execution T1204.002 Malicious File Execution: User Execution: Malicious JavaScript

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The critical ClamAV detection of 'Pdf.Exploit.Agent-36086' strongly suggests exploit activity. The presence of a large comment-padded JavaScript eval stager further supports the execution of malicious code. The primary intent appears to be the exploitation of vulnerabilities within the PDF reader to download and execute further payloads.

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
4eb16b329b90b9866825d60ea0bf2b035a1c02406a9aa8ccfcf3fc96302e34f0
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627086 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).