Malicious PDF — malware analysis report

Static analysis result for SHA-256 1be184e21cf048bd…

MALICIOUS

PDF

15.7 KB
MD5: d19156513457ff6690ae97c4115ef64d SHA-1: 13f61bf49108a5bb6bff51d2e4403b043bea760e SHA-256: 1be184e21cf048bdc16bb59e012fa01a9b258aced6858674757fc2832ddcce69
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1204.001 Malicious Link

The critical ClamAV detection of 'Pdf.Exploit.Agent-36086' strongly indicates a malicious PDF exploit. The presence of embedded JavaScript, specifically a large comment-padded eval stager using `eval()` and `String.fromCharCode`, points to a downloader or dropper mechanism. This script is designed to execute arbitrary code, likely fetching and running a second-stage payload. The document body is unreadable, but the technical indicators are sufficient to infer a malicious exploit delivery.

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
caef52cc0d2b3af19c96e33cd720c3e87cca52f2abde9776bd2310dbefdd84d1
pdf-javascript-stream PDF /JS object 6 at offset 0x143 424746 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).