Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c9ca1646b029b82…

MALICIOUS

PDF

47.2 KB Created: 2021-06-03 18:23:29 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: 8a32780e4440bfe9fde7d9b452e22c4a SHA-1: 88d017607d45601bddd22f977bd707e50bfe2323 SHA-256: 9c9ca1646b029b820daaea718818f62e736fe6797cd7ed54c781fedd1e844f33
82 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF document that displays a fake CAPTCHA to trick the user into interacting with it. It contains an embedded URI pointing to a suspicious URL, likely intended to download a second-stage payload. The ML classifier also flagged this PDF as malicious, increasing confidence in its malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9769

Heuristics 4

  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • External URI info PDF_URI
    PDF contains an external URL action
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://netcdn.online/app/431946152/roblox-promo-codes-free-robux-game-hack
    • https://www.wcauk.org/uploads/files/files/how-to-get-free-coins-on-coin-master_GM406889139.pdf
    • https://www.wcauk.org/uploads/files/files/coin-master-free-spins-and-coins-haktuts_GM406889139.pdf
    • https://www.wcauk.org/uploads/files/files/free-robux-hack-no-human-verification-or-survey_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/free-minecraft-survival-server_GM479516143.pdf
    • https://www.wcauk.org/uploads/files/files/master-free-spins-and-coins_GM406889139.pdf
    • https://www.wcauk.org/uploads/files/files/minecraft-svg-images-free_GM479516143.pdf
    • https://www.wcauk.org/uploads/files/files/codes-how-to-get-free-robux_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/is-roblox-free-on-nintendo-switch_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/roblox-free-robux-codes_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/free-tiktok-app_GM835599320.pdf
    • https://www.wcauk.org/uploads/files/files/rbl-gg-free-robux_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/coin-master-hack-game_GM406889139.pdf
    • https://www.wcauk.org/uploads/files/files/free-minecraft-account_GM479516143.pdf
    • https://www.wcauk.org/uploads/files/files/free-robux-generator-2021_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/free-robux-exe_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/free-coin-and-spin-for-coin-master_GM406889139.pdf
    • https://www.wcauk.org/uploads/files/files/roblox-its-free_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/free-robux-codes-2021-not-used_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/robux-hack-generator_GM431946152.pdf
    • https://www.wcauk.org/uploads/files/files/minecraft-bedrock-hacks_GM479516143.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00005180.bin
51926b3141d27e445d8ee3835b095e26dca753959a7c8f7cbfced375a736ecae
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5180 24936 bytes
font_01_sfnt_off00008af9.bin
baad2f3f6808f4af03fa9398e38c580c8d846f7f773a947d8cc1f39b2753d31a
pdf-font-stream PDF embedded font (sfnt) at offset 0x8AF9 2844 bytes
font_02_sfnt_off000094bb.bin
3ed324e585500d41944ebd93500991c566830021fec9c5a8323b790459c3443f
pdf-font-stream PDF embedded font (sfnt) at offset 0x94BB 18676 bytes