Malicious PDF — malware analysis report

Static analysis result for SHA-256 71d5d735f63046c0…

MALICIOUS

PDF

45.1 KB Created: 2021-06-11 03:30:32 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 82b04f5b77266bc5ca49823f936bce12 SHA-1: 7be4f2fa29cd92dc8a0ca718abeff7ea841cb1be SHA-256: 71d5d735f63046c0414b8da2147658167e27e88dd8718476f58e5a928502b23c
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document contains a lure for 'Free Robux' and links to a known malicious redirector infrastructure. The document body and embedded URLs suggest a social engineering attempt to trick users into visiting potentially harmful websites. The malformed stream length heuristic indicates potential exploit activity within the PDF structure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9890

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.tw/app/431946152/free-robux-202120210-woking-feb-2021-game-hack In PDF document text
    • http://nebraskahospitalityhalloffame.com/images/free-robux-without-verification-2021_GM431946152.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/pubg-uc-official-app_GM1330123889.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/free-spin-in-coin-master_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/free-robux-rewards_GM431946152.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/free-college-textbooks-tiktok_GM835599320.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/coin-master-free-spin-link-today-2021_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/coin-master-free-spins-link-2021-today_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/how-to-get-free-robux-fast-and-easy_GM431946152.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/how-to-get-free-spins-on-coin-master-android_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/hack-to-send-gold-cards-on-coin-master_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/claim-coin-master-free-spins_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/rbx-gg-free-robux_GM431946152.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/the-final-stand-2-roblox-hack_GM431946152.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/coin-master-free-spins-app_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/coin-master-free-gifts_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/fbchampion-com_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/descargar-roblox-hack-robux_GM431946152.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/coin-master-free-chest-link_GM406889139.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/which-pubg-uc-is-best_GM1330123889.pdfIn PDF document text
    • http://nebraskahospitalityhalloffame.com/images/coin-master-free-online-game_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_off00005165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5165 24860 bytes
SHA-256: 50336949050aef808309e1228b688aeef326111787942669f41420763535f7c8
font_01_sfnt_off00008ab9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8AB9 19192 bytes
SHA-256: 067efc7014c37350089e6c1ea281f37a9378bd557d56e662dbfa5817eebd780c