Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb831d58ac99e0de…

MALICIOUS

PDF

35.2 KB Created: 2021-06-22 06:22:28 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: b641721d9fefd2da8a96f9ece0417309 SHA-1: a54693d9df64a9ee98cfed28c36152999ee6c8bb SHA-256: fb831d58ac99e0deb2296d038615b23c87109eff2e67c920571299d300bb7453
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to known malicious redirectors and lures users with promises of game hacks and free currency. The document body and embedded URLs suggest a scam aimed at tricking users into visiting malicious sites, likely to download further malware or engage in credential harvesting. The ML classifier also strongly indicated maliciousness.

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.co/app/431946152/how-to-hack-roblox-games-on-mobile-game-hack In PDF document text
    • http://bufbd.org/images/roblox-bc-free-account_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/coin-master-spin-pattern_GM406889139.pdfIn PDF document text
    • http://bufbd.org/images/how-to-host-a-minecraft-server-for-free_GM479516143.pdfIn PDF document text
    • http://bufbd.org/images/free-robux-promo-codes-list_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/free-obc-thumbnail-roblox_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/robux-free-gift-card-org-hack_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/hack-amievenalive-in-roblox_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/where-to-get-free-robux_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/free-robux-no-verification-needed_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/hacks-en-csgo-roblox_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/coin-master-hack-spin-generator-tool_GM406889139.pdfIn PDF document text
    • http://bufbd.org/images/free-spins-on-coin-master_GM406889139.pdfIn PDF document text
    • http://bufbd.org/images/offers-to-complete-and-get-free-spins-in-coin-master_GM406889139.pdfIn PDF document text
    • http://bufbd.org/images/free-robux-app-2021_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/free-robux-only-half-to-use-username_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/blox-fish-free-robux_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/how-to-get-free-robux-pastepin_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/cheat-roblox-vehicle-simulator_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/free-robux-generator-for-kids_GM431946152.pdfIn PDF document text
    • http://bufbd.org/images/robux-points-get-free-robux_GM431946152.pdfIn PDF document text
    • https://www.roblox.com/my/tasksIn 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_off0000302e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x302E 22952 bytes
SHA-256: f98fb100afc1a2d71ecf68581ba67bc313ed96137c5d07571c8a2133dacdea04
font_01_sfnt_off000063bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x63BB 19396 bytes
SHA-256: 276fd744454ed875e8ee6ed816b3faec813d33b0d24f348a94368f37fae40861