Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ad8f8aa16636664…

MALICIOUS

PDF

118.7 KB
MD5: 91d2877b543b0f9e0df8ef9f60824992 SHA-1: 6d7a53c561bce0fde4ed5f717890813152de84d8 SHA-256: 7ad8f8aa16636664a4f0c3eb7243ed89daf77ebd8d67305c49b2c50b1feb23d2
166 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, including a large, comment-padded eval stager. This indicates the script is designed to obfuscate its true functionality, which is typical for malware downloaders. The presence of `eval()` and `String.fromCharCode` further supports the interpretation that the script decodes and executes arbitrary code. ClamAV detection as 'Pdf.Exploit.Agent-36086' confirms its malicious nature. The primary attack pattern involves exploiting PDF vulnerabilities to run malicious JavaScript, likely to download and execute a second-stage payload.

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
bb0129c565042dc17cc25e46ffe62f7cfb6362b92e964c8e1eda0692481a2463
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626972 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).