Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b98b8904f735d9…

MALICIOUS

PDF

34.8 KB Created: 2021-07-03 13:41:46 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 3c9501af322d8a237d5d77494ceca28d SHA-1: a7550c294840117b5a4873daeb5c3d1463bbc26a SHA-256: 21b98b8904f735d9d0b69eb4a3b68b693c4618c792b5e735ae9b59f72954a974
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains multiple links to a known malicious redirector, masquerading as a 'robux hack' or 'game hack'. The document body and embedded URLs strongly suggest a lure for users seeking in-game currency or cheats, which is a common social engineering tactic. The primary malicious action observed is directing the user to a potentially harmful external resource.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 4

  • PDF links to a 'free generator / game hack' redirector critical PDF_GAME_HACK_REDIRECT_LURE
    PDF's clickable action targets a redirector of the form /app/<id>/<slug>-game-hack — the landing-page shape of a large SEO 'free spins / generator / game hack' lure family that funnels victims through rotating disposable hosts to a malware/scam payload. The multi-link variants also trip ML/link-farm rules; this catches the single-link variants that otherwise score clean. CRITICAL on its own: the /app/<id>/<slug>-game-hack path shape is unambiguous scam infra, and the host rotates so a host-list match can't be relied on.
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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
  • 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 http://netcdn.tw/app/431946152/robux-hack-no-verification-game-hack In PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/roblox-infinite-money-hack_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/can-you-still-get-minecraft-windows-10-for-free_GM479516143.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/optifine-pe_GM479516143.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/mcmaster-club-coin-master-hack_GM406889139.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/how-to-get-free-robux-youtube_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/roblox-hack-download_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/roblox-free-robux-scam-discord_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/minecraft-tiktok-hacks_GM479516143.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/free-tiktok-fans-hack_GM835599320.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/earn-robux-for-roblox_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/breaking-point-hacks-roblox_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/free-roblox-alts-to-bypass-account-age_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/free-spins-coins-coin-master_GM406889139.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/coin-master-card-collection-hack-apk_GM406889139.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/tiny-tanks-cheats-roblox-2021_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/free-roblox-accounts-with-bloxburg_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/minecraft-pe-hacks_GM479516143.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/how-do-you-get-free-food-in-coin-master_GM406889139.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/free-robux-hack-no-verification-2021_GM431946152.pdfIn PDF document text
    • https://bioscience.kyst.com.tw/image/data/files/roblox-deadzone-item-hack_GM431946152.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00003199.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3199 22128 bytes
SHA-256: aeb8d48c8c6373f4dc464ec51bbfc9d35351235dcef898d73c923f438b21d134
font_01_sfnt_off000062d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x62D7 19080 bytes
SHA-256: d232f6da93b975725b0e6de4d1ead99b7c862a359b76aa44f8f2076ca8d9907b

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