Malicious PDF — malware analysis report

Static analysis result for SHA-256 21fa599518681f12…

MALICIOUS

PDF

41.5 KB Created: 2021-05-13 06:53:19 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: b03725e36f0954103cd89b634dd6eddf SHA-1: 8b4f82f86a5cdd5128cb47380e88f70a78ce06f4 SHA-256: 21fa599518681f12894ab576e3bbb3b0cac63bdfc3fd0be5f777b69f53b69176
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains multiple links to known malicious redirectors and websites offering game hacks and free in-game currency, indicating a phishing or scam attempt. The malformed stream length and ML classifier flagging further support its malicious nature. The document body, though heavily obfuscated, contains references to 'Coinmaster' and URLs related to game exploits, reinforcing the lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • 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.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.xyz/app/406889139/coinmaster-game-hack In PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/is-it-possible-to-get-free-robux_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/minecraft-free-computer-game_GM479516143.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/how-to-get-100-robux-for-free_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/coin-master-free-cards-hack_GM406889139.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/robux-codes_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/free-vpn-for-minecraft_GM479516143.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/robux-gratis_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/coin-master-daily-free-spins-link-today_GM406889139.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/get-free-robux-without-human-verification_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/ww-robux_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/apps-that-give-you-free-robux_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/how-to-get-more-robux-for-free_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/free-robux-games-on-roblox_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/coin-master-free-link-spin_GM406889139.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/how-to-hack-coin-master-ios-no-jailbreak_GM406889139.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/coin-master-free-spin-link-new_GM406889139.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/coin-master-hack-2021_GM406889139.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/minecraft-hack-2021_GM479516143.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/getrobux-ninja_GM431946152.pdfIn PDF document text
    • https://jasabuatlabel.com/ckfinder/userfiles/files/coin-master-free-spins-and-coins-2021_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
font_00_sfnt_off000048f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x48F8 25120 bytes
SHA-256: 94957e72f90d95c4036d594502cb0a81d3b8cb1414b29234496036d291940947
font_01_sfnt_off00008173.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8173 17808 bytes
SHA-256: af208cdb45bd073d7b5ba90b2b5d7fe18c625e7bd90d48e59b2ee82d337b8146

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