Malicious PDF — malware analysis report

Static analysis result for SHA-256 71661b855adfcf5f…

MALICIOUS

PDF

47.7 KB Created: 2021-06-03 06:55:21 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 7a6bcb45b56df77a643b896b9e0dae21 SHA-1: d8c7df508b4eb856a961ef090a414d6ddf4f837b SHA-256: 71661b855adfcf5f5e970431e4e796c647622d47d455b12c96c678e19d27a88a
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains multiple links to external websites, including a known malicious redirector, under the guise of offering free Robux for Roblox. The ML classifier also flagged this PDF as malicious. The presence of embedded links and the lure of free in-game currency strongly suggest a phishing or scam attempt designed to redirect users to potentially harmful content or initiate a download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9769

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 https://netcdn.online/app/431946152/earn-free-robux-on-roblox-game-hack In PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/coin-master-free-coins-link-2021-deutsch_GM406889139.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/how-to-download-minecraft-for-free-ios_GM479516143.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/minecraft-realms-free-codes_GM479516143.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/lucky-patcher-coin-master-hack_GM406889139.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/roblox-rules_GM431946152.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/get-free-robux-today_GM431946152.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/how-to-hack-someones-roblox-account_GM431946152.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/free-spins-coin-master-generator_GM406889139.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/minecraft-free-download-mac-full-version_GM479516143.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/robux-com-free_GM431946152.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/free-online-minecraft-server_GM479516143.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/coin-master-hack-apk_GM406889139.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/free-coins-coin-master-hack_GM406889139.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/minecraft-for-chromebook-free_GM479516143.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/free-robux-without-verify_GM431946152.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/free-robux-giveaway-live_GM431946152.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/free-tiktok-followers-without-verification_GM835599320.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/minecraft-free-download-apk-softonic_GM479516143.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/coin-master-no-download-app-but-play-for-free_GM406889139.pdfIn PDF document text
    • http://www.gzsuihe.com/Public/upload/editorfiles/haktuts-2021-coin-master-free-spin-link_GM406889139.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000053e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x53E6 24152 bytes
SHA-256: ff5d8d5eb01769d8a3dada4761086e8bae2f1e1bc54a7fd36f806295094e06fd
font_01_sfnt_off00008af7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8AF7 3656 bytes
SHA-256: 63a179d8a9645bea05c6d53b1776faf4e4a7281930de6cf484e639846bec2e20
font_02_sfnt_off000097b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x97B1 18316 bytes
SHA-256: 9c0981cacc72906997edc94ef8681ff328413c242d975763da1b98cbde4aeec5