Malicious PDF — malware analysis report

Static analysis result for SHA-256 71de86b3efdf9ef1…

MALICIOUS

PDF

32.8 KB Created: 2021-06-24 06:17:42 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 9da6f7542a760a6870b521a531c9fcb0 SHA-1: 9f4a413beeea0f66c8cd50357c7823751c6712e6 SHA-256: 71de86b3efdf9ef1f22ddf903f9ebcce2b17b1caa165563d6ed481b4b1c5232e
180 Risk Score

Malware Insights

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

The PDF contains a malformed stream and links to a known malicious redirector, suggesting an exploit attempt. The document body and embedded URLs promote 'free Robux' and game hacks, indicating a lure to a phishing or malware distribution site. The ML classifier also flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9824

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 http://netcdn.co/app/431946152/free-robux-now-game-hack In PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/coin-master-invite-friends-free-spins_GM406889139.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/play-games-for-robux_GM431946152.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/coin-master-hack-pc-free_GM406889139.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/coin-master-online-hack-generator_GM406889139.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/coin-master-hack-2021_GM406889139.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/free-minecraft-codes_GM479516143.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/coin-master-heaven-free-spins_GM406889139.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/coin-master-hack-spin-ios_GM406889139.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/make-free-robux_GM431946152.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/roblox-free-items_GM431946152.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/robux-fun-hack_GM431946152.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/free-spins-and-coins-coin-master-2021-link_GM406889139.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/coin-master-free-coins-and-spins-2021_GM406889139.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/free-roblox-hack_GM431946152.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/coin-master-hack-without-verification-code_GM406889139.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/roblox36com-free-robux_GM431946152.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/roblox-report-hacker_GM431946152.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/discord-servers-free-robux_GM431946152.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/roblox-vehicle-simulator-how-to-get-free-cars_GM431946152.pdfIn PDF document text
    • https://www.smkpgri2bdg.sch.id/new/public/ckfinder/userfiles/files/free-800-robux_GM431946152.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_off00002ada.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2ADA 22132 bytes
SHA-256: 9c59bf8106270253a4ec35e583ad6927e1b5f14c2c1ddc23c259823c940c6979
font_01_sfnt_off00005bba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5BBA 18880 bytes
SHA-256: 5812b0d0ccf9dc87c8d54428ef2763728ec286cf096b79da6b6c7cfb1f79e008