Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b546cd06a84662…

MALICIOUS

PDF

35.4 KB Created: 2021-07-04 12:40:42 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 71e94a447bf86844eafdf3df60970d9e SHA-1: 90dec556a30912409feed71a3783209bb2e5f761 SHA-256: 81b546cd06a84662904e7fb38fea4480243d96753e17b7d9eb4abd0495310dea
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains multiple links to known malicious redirectors and lures users with promises of game hacks and free spins. The primary link, http://netcdn.tw/app/406889139/como-sacar-buen-puntaje-en-juego-coin-master-free-spins-game-hack, is identified as a game hack redirector. While no scripts were explicitly extracted, the PDF structure and embedded URLs strongly suggest a phishing or social engineering attack aimed at driving traffic to potentially malicious sites.

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/como-sacar-buen-puntaje-en-juego-coin-master-free-spins-game-hack In PDF document text
    • https://www.ruchya.com.tw/upload/files/hack-coin-master-apk-32-download_GM406889139.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/free-minecraft-codes_GM479516143.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/hack-de-roblox-2021_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/free-catalogs-on-roblox_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/free-roblox-clothes-promo-codes_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/get-everything-free-roblox-console-pastebin_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/how-to-get-free-robux-on-pc_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/check-cashed-hack-not-roblox_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/free-spins-coin-master-app_GM406889139.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/coin-master-32-mod-hack-unlimited_GM406889139.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/download-coin-master-hack_GM406889139.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/free-roblox-dislike-bots_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/free-robux-hack-no-human-verification_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/minecraft-free-android_GM479516143.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/how-to-get-free-robux-without-verification-or-surveys_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/pubg-90-uc_GM1330123889.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/coin-master-hacks-no-surveys_GM406889139.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/roblox-studio-free-robux_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/rbxoffers-com-earn-free-robux_GM431946152.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/coin-master-latest-version-hack_GM406889139.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
stream_002_off0000315e.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x315E 22976 bytes
SHA-256: d39d509a957d7168f1bd41771dff8fee9879f59d5dfc0fabedae129538d7d2f6
font_01_sfnt_off0000650e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x650E 19300 bytes
SHA-256: 558b0016b5b6051100e6d5fa06c14f0a97801632f586348ab5c9d047f9de8e21

Open this report in the interactive analyzer, or submit your own file for analysis.