Malicious PDF — malware analysis report

Static analysis result for SHA-256 93fc3ca7a24c100e…

MALICIOUS

PDF

7.7 KB
MD5: bfa58630a1e600b6392b48bfddeb8501 SHA-1: 3f2c90d4fe41ebafa2d300d551b0c7ac704600a3 SHA-256: 93fc3ca7a24c100e3c4cbbd75f2f1cb6cf3cd47b690d8162cbd25ba8e1804f87
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The critical ClamAV detection and high PDF_JS_OBFUSCATED_DROPPER heuristic indicate this PDF is designed to exploit vulnerabilities and deliver a second-stage payload. The embedded JavaScript, though obfuscated, is identified as a dropper. The primary intent appears to be the download and execution of further malicious content, as suggested by the dropper heuristic. No specific family could be confidently identified.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-35902 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35902
  • 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
3cf6a22459cda11e607fc9e0dc0c88d01a8425e26488ff87df38d855ceb4dccf
pdf-javascript-stream PDF /JS object 5 at offset 0x148 465 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
851a87bd663634d437917dff35e70e1c831c20e421e13c996694c00a8e0ba66a
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x19BA 1758 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
deobfuscated.js
dd0cc73fd3387ed6b2e49a7a22ad5844052c97153a5742c36fa962e0705559e4
deobfuscated-js PDF JavaScript deobfuscation pass 22264 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).