Malicious PDF — malware analysis report

Static analysis result for SHA-256 bca88dfe419aeb19…

MALICIOUS

PDF

118.4 KB
MD5: d013d868bc7a52416a22673de99f94f7 SHA-1: 10caca041ac7ec479e034ea4d540958292958997 SHA-256: bca88dfe419aeb195226250e616a1b6f6cabea74ba69bea9233764b78ef90f99
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.002 Malicious JavaScript

The PDF file contains embedded JavaScript, as indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_EVAL'. A critical ClamAV detection ('Pdf.Exploit.Agent-36086') further confirms its malicious nature. The presence of a large, comment-padded JavaScript eval stager suggests a sophisticated attempt to obfuscate the execution of malicious code. The primary intent appears to be the download and execution of a second-stage payload, facilitated by the embedded JavaScript.

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
282ac4d6b8b27857b4a5c8a5f4b6c36c34a3bf097d7b2df7aaedd8f2309a4c20
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627138 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).