Malicious PDF — malware analysis report

Static analysis result for SHA-256 831a619edd07216c…

MALICIOUS

PDF

45.0 KB Created: 2021-06-09 05:49:41 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: b17e7d910d1eb8ed438faba480e905b1 SHA-1: a0904175a97e8413ddc597ee7cee588cb904b3b8 SHA-256: 831a619edd07216c8f70de124183239e67816646c2c01bb79186f297bcb56e94
168 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains an embedded URL pointing to a 'free robux generator' which is a common lure for malicious downloads or phishing. The ML classifier strongly flagged this PDF as malicious, and the document body text reinforces the lure by mentioning a quiz game. While no scripts were explicitly extracted, the presence of embedded URLs and the ML detection suggest a high likelihood of malicious intent, possibly involving a JavaScript exploit or a direct link to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9865

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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-generator-quiz-game-hack In PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/spin-link_GM406889139.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/wurst-download_GM479516143.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/free-robux-script_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/claim-robux_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/tiktok-free-view-quest_GM835599320.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/free-coin-master-spin-app_GM406889139.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/how-to-hack-someone-on-roblox_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/free-robux-codes-no-verification_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/microsoft-bing-robux_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/free-robux-site_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/freerobux-hack-us_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/minecraft-com-free_GM479516143.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/minecraft-mojang-free_GM479516143.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/coin-master-free-spins-2021_GM406889139.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/coin-master-hack-online-2021_GM406889139.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/roblox-games-that-give-you-free-robux_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/want-free-robux-copy-and-paste_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/rbx-land-free-robux_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/hitbox-hack-roblox_GM431946152.pdfIn PDF document text
    • http://digilib.ulm.ac.id/pusat/repository/coin-master-hack-without-downloading-apps_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_004_off0000517e.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x517E 25796 bytes
SHA-256: f4a4ff09b1fcb862722255ba80f74ba2a651c2a0754d507484d7094faffacba0
font_01_sfnt_off00008bf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8BF1 18708 bytes
SHA-256: 43079355cd8fb3eba19e04e206dfe49a3d318abf03d8fdacb6f39985cc3d735b

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