Malicious PDF — malware analysis report

Static analysis result for SHA-256 328690f3a555d399…

MALICIOUS

PDF

118.5 KB
MD5: 56edd4c1985f7b105e35462d3cfe6f3c SHA-1: 49fba9b086a2ebff73e09223009fed7207b7a0c9 SHA-256: 328690f3a555d3995fd448bc730463e86572cf4252ae462d89282b1c34cccce2
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.002 Spearphishing Attachment

The PDF contains embedded JavaScript, including a large comment-padded eval stager, indicating an attempt to obfuscate and execute malicious code. The presence of `eval()` and `String.fromCharCode` further supports this. ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly suggests an exploit or payload delivery mechanism. The attack pattern is consistent with a malicious PDF designed to exploit vulnerabilities or download further malware.

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
6229720c0ae8a610f13f293d6a6d16cdd0bcc9feb456c53f23f3fbff2213d89c
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626893 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).
stream_002_off0001d854.bin
e5b87fcf8fd45136f744a2bbdb0ff8eaca88641a594494a723cd825cfff99399
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1D854 200 bytes