Malicious PDF — malware analysis report

Static analysis result for SHA-256 51b61931ea3a0a32…

MALICIOUS

PDF

34.0 KB Created: 2021-07-04 03:52:46 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: d701b36cb9bb85d2b9d1637cac46729e SHA-1: a7498817bc35c0a6e4c20a5be56ee812d7464541 SHA-256: 51b61931ea3a0a32c824b5d7599f04d65f9ce9bed77ac234750851941792859c
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document employs a lure of 'Free Hacks For Coin Master' to entice users into clicking a link. The link, http://netcdn.tw/app/406889139/free-hacks-for-coin-master-game-hack, is identified as a malicious redirector, indicating a phishing or malware distribution attempt. The presence of multiple related PDF links suggests a campaign distributing similar lures. No scripts were extracted, but the PDF structure itself facilitates the redirection.

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/406889139/free-hacks-for-coin-master-game-hack In PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/mcpe-optifine_GM479516143.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/roblox-free-r-obux_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/roblox-cheats-2021-skywars_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/hype-dance-roblox-free_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/games-like-minecraft-but-free_GM479516143.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/roblox-hack-bars_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/coin-master-daily-free-spins-link-haktuts_GM406889139.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/link-coin-master_GM406889139.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/roblox-hack-tool-account_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/coin-master-free-spin-and-coin-link-haktuts-hacking-news_GM406889139.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/robux-cheats-without-human-verification_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/raindrop-free-roblox_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/roblox-script-hack_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/hack-game-coin-master_GM406889139.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/free-roblox-card_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/wahoo-free-robux_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/2021-roblox-got-hacked_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/free-fans-on-tiktok_GM835599320.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/free-roblox-character-editor_GM431946152.pdfIn PDF document text
    • http://www.6636.com.tw/ad6636/upload/files/hacks-for-pet-simulator-on-roblox_GM431946152.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off00003059.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x3059 22576 bytes
SHA-256: 2dc6e9e6d447c481079597279aa1e6643f8d1cfd5ea88c2061a358e0cab10162
font_01_sfnt_off000062bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x62BC 18168 bytes
SHA-256: 1e436942c22cf5f1ddb993b5625de9063034e514cb54256dfb31bec93a9ee0e1

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