Malicious PDF — malware analysis report

Static analysis result for SHA-256 36baff4a5282eaef…

MALICIOUS

PDF

46.6 KB Created: 2021-06-08 11:05:52 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: d66d0ed504679f180a54687cde05fa8f SHA-1: 17e1825232cc81e834fce5769fdc050da9e81fcd SHA-256: 36baff4a5282eaef0cc2fde5eceb4f4727895eab7b73054cf98dca852e2b580a
82 Risk Score

Malware Insights

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

The document presents a fake CAPTCHA or human verification prompt to trick users into downloading additional files, likely malicious. It contains multiple embedded URLs pointing to suspicious domains, suggesting a phishing or malware distribution attempt. The ML classifier also flagged this PDF as malicious with high confidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9748

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.tw/app/431946152/free-game-for-roblox-game-hack
    • http://juscor.com.br/ckfinder/userfiles/files/roblox-games-that-give-you-free-robux_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/coin-master-free-spins-no-survey_GM406889139.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/how-to-hack-roblox-for-robux_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/coin-master-hack_GM406889139.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/how-to-get-free-robux-with-no-verification_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/free-coins-coin-master-iphone_GM406889139.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/coin-master-free-daily-spins-link_GM406889139.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/80-free-spins-coin-master_GM406889139.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/get-free-robux-gg_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/free-robux-no-verification-required_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/flame-gg-free-robux_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/coin-master-free-spin-and-trading_GM406889139.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/lots-of-robux_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/coin-master-hack-online-pc_GM406889139.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/free-account-roblox-with-robux_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/how-to-hack-a-roblox-account-easy_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/free-minecraft-account-list_GM479516143.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/free-robux-games-that-actually-work-2021_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/free-roblox-accounts-generator_GM431946152.pdf
    • http://juscor.com.br/ckfinder/userfiles/files/free-minecraft-hacks_GM479516143.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00004f8f.bin
29fe3315efdc80966d0d0959b0d6d97e48dcb8fbdf55093f1f9f99797450ae1e
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4F8F 25692 bytes
font_01_sfnt_off000088a5.bin
eb230542719c96b42e3fd8bb01e35f13ebd5f02629049da3a58e7fd7607bf48a
pdf-font-stream PDF embedded font (sfnt) at offset 0x88A5 2940 bytes
font_02_sfnt_off000092b5.bin
1bf82dd8afdb27f94ed8c62bb10c3663fee25409811c2bad390d43823afe3328
pdf-font-stream PDF embedded font (sfnt) at offset 0x92B5 18436 bytes