Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca11ee15853517bf…

MALICIOUS

PDF

44.8 KB Created: 2021-06-10 18:43:52 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: c1b98d711045e46fb1d74e357f05b787 SHA-1: d260786106a0ddece8000fe6c30c8b6a83e7c50f SHA-256: ca11ee15853517bf21c66e69d5fff5eb4ea9b7de6a56f6c0d19274a35c233702
82 Risk Score

Malware Insights

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

The document presents a fake CAPTCHA or human verification prompt to trick users into downloading a payload, as indicated by the SE_FAKE_CAPTCHA heuristic. The embedded URL, https://netcdn.tw/app/431946152/cheat-manager-free-robux-game-hack, likely hosts the malicious second-stage content. While no scripts were explicitly extracted, the PDF structure and ML classification suggest malicious intent, potentially involving exploitation for client execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9865

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/cheat-manager-free-robux-game-hack
    • https://www.croydex.com/uploads/files/files/roblox-robux-hack_GM431946152.pdf
    • https://www.croydex.com/uploads/files/files/free-roblox-com_GM431946152.pdf
    • https://www.croydex.com/uploads/files/files/how-to-get-minecraft-realms-for-free_GM479516143.pdf
    • https://www.croydex.com/uploads/files/files/how-to-make-a-group-on-roblox-for-free_GM431946152.pdf
    • https://www.croydex.com/uploads/files/files/minecraft-classic-free_GM479516143.pdf
    • https://www.croydex.com/uploads/files/files/free-minecraft-alts_GM479516143.pdf
    • https://www.croydex.com/uploads/files/files/cmaster-club-coin-master-hack_GM406889139.pdf
    • https://www.croydex.com/uploads/files/files/minecraft-free-play-now_GM479516143.pdf
    • https://www.croydex.com/uploads/files/files/how-to-get-free-robux-and-tickets-on-roblox-2021_GM431946152.pdf
    • https://www.croydex.com/uploads/files/files/spin-coin-master-free_GM406889139.pdf
    • https://www.croydex.com/uploads/files/files/robux-hack_GM431946152.pdf
    • https://www.croydex.com/uploads/files/files/coin-master-free-spin-link-app_GM406889139.pdf
    • https://www.croydex.com/uploads/files/files/focus-points-hack-roblox-dance-your-blox-off_GM431946152.pdf
    • https://www.croydex.com/uploads/files/files/spin-hack-for-coin-master_GM406889139.pdf
    • https://www.croydex.com/uploads/files/files/coin-master-shield-hack_GM406889139.pdf
    • https://www.croydex.com/uploads/files/files/free-robux-no-verification-no-download_GM431946152.pdf
    • https://www.croydex.com/uploads/files/files/tiktok-free-likes-and-followers-2021_GM835599320.pdf
    • https://www.croydex.com/uploads/files/files/www-coinmaster-com_GM406889139.pdf
    • https://www.croydex.com/uploads/files/files/coin-master-heaven-links-free-spins_GM406889139.pdf
    • https://www.croydex.com/uploads/files/files/login-robux_GM431946152.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00004e61.bin
523e9853eadeedfc286b9330e0cbff2f2d07ccbe32da5877fb81a9f314060b2b
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4E61 26200 bytes
font_01_sfnt_off00008a90.bin
125c55ae2bed405adaf6b515ba662c1ce360b7e633cbe6774b13f0b3204b52fc
pdf-font-stream PDF embedded font (sfnt) at offset 0x8A90 18996 bytes