Malicious PDF — malware analysis report

Static analysis result for SHA-256 ee2a58a55c864bb3…

MALICIOUS

PDF

15.7 KB
MD5: 4360d65a3f7fd0468075e4543351cf17 SHA-1: 187702fd2471a0538727eb7b8a0f00887c7084a8 SHA-256: ee2a58a55c864bb3fed3a2c0f6ad60e12ccf0b964d9de8a8582dda14106c170e
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The presence of a 'Large comment-padded JavaScript eval stager' suggests an attempt to obfuscate malicious code. The ClamAV detection 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The embedded JavaScript streams, named 'javascript_obj0006_000.js' and 'legacy_pdfkit_stage_000.js', are likely responsible for executing the exploit and downloading further malicious content.

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
1546a9927897643510659ea22c834eba733a55323407ac9c84885a2e70953077
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425689 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
ad9a62651f846f8bdaf5bfc0c0d4f88a4c3ff28d59bf7f4d97c71aee460c5a12
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 558 long base64-like blob(s).