Malicious PDF — malware analysis report

Static analysis result for SHA-256 ce6c0b52ba58c6a9…

MALICIOUS

PDF

8.0 KB
MD5: 4e76a6f833a8a4c309eb503f99e17877 SHA-1: 21921f84541b72daaa86e54898b999178c5b24af SHA-256: ce6c0b52ba58c6a94a53e29ebb28afa9854560533b8d49da2ae818001ba67f59
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains heavily obfuscated JavaScript, identified by multiple heuristics including 'PDF_JS_OBFUSCATED_DROPPER'. This script is designed to act as a dropper, likely downloading and executing a second-stage payload. The ClamAV detection 'Pdf.Exploit.Agent-35901' further confirms its malicious nature. The exact download URL or execution command could not be confidently reconstructed due to the obfuscation.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-35901 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35901
  • Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER
    PDF JavaScript shows 5 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_codec_loop, hex_dashed_payload, incremental_eval_build, repeated_pluginschk. This is strongly consistent with pre-2011 Adobe Reader PDF droppers — OpenAction JS reads encoded data from annotation subjects, decodes it through one or more hex / base-N loops, and invokes eval indirectly (method name built one character at a time). The actual CVE is hidden in the final decoded layer and is not visible via static analysis.
  • 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)
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (matched in decompressed 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
4718a27c2224fc36bf24f8e8e04598f1ad78adce4401c7be2708318738a6983d
pdf-javascript-stream PDF /JS object 5 at offset 0x148 469 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
5b9f3f9e36e2ea42e8e88fa94848459863c863a351a322613bb9294a828c6b7f
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1B0C 1803 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
deobfuscated.js
40204c86970a6fd5129bbfec1dd9ea784dab3007f453ca0cf94b4cb27ee7b9d5
deobfuscated-js PDF JavaScript deobfuscation pass 24192 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).