Malicious PDF — malware analysis report

Static analysis result for SHA-256 da3d7ec660dacc37…

MALICIOUS

PDF

15.6 KB
MD5: 2766a216d4389d24d0a6ff68b6d6f273 SHA-1: 4a60a6b634a0396dc1a3124b0d20ccb6da859cf3 SHA-256: da3d7ec660dacc37029c2e462b8f2b4b12fcb428d0c6aed04cb2a77c9804ea5d
158 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains obfuscated JavaScript, flagged by multiple high-confidence 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.Dropper.Agent-7311559-0' further confirms its malicious nature as a dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • ClamAV: Pdf.Dropper.Agent-7311559-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7311559-0
  • Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER
    PDF JavaScript shows 3 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_dashed_payload, 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.
  • 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
a3319192cac6d4dc4eeb6af2d736b0ffec979b23116a003bc7c23382761c32a5
pdf-javascript-stream PDF /JS object 5 at offset 0x148 733 bytes
legacy_pdfkit_stage_000.js
f099691d11e689824d58a4abc59fd6fe9028d7db5dd57a1b0a355e7eef3419f7
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1A80 12357 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
97adc3633ce6981eb35789ab558b0aa1e010d3f8d3f50c0915cfacbc6b2d5001
deobfuscated-js PDF JavaScript deobfuscation pass 103616 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).