Malicious PDF — malware analysis report

Static analysis result for SHA-256 c821d5864884d5d4…

MALICIOUS

PDF

42.7 KB Created: 2021-05-15 05:11:53 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 4ec65510d534beed0fbaa881303c93b2 SHA-1: c01369354b7dea8f6353095876815c8837f79817 SHA-256: c821d5864884d5d4dc53bad324351bd93bac76f68fff0ddc3b11107a81e361eb
222 Risk Score

Malware Insights

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

This PDF document employs social engineering tactics by promising free game currency and hacks, a common lure for malicious content. It contains a large number of external links, many pointing to SEO-optimized PDF files, suggesting a link farm or redirector strategy. The presence of a fake CAPTCHA and browser update lure further indicates an attempt to trick the user into executing malicious actions or downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 7

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • PDF links to a 'free generator / game hack' redirector high 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.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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/431946152/free-robux-without-downloading-anything-game-hack PDF link annotation
    • http://linde-erbach.de/images/what-are-points-for-in-roblox_GM431946152.pdfIn PDF document text
    • http://linde-erbach.de/images/best-minecraft-hacked-client-2021_GM479516143.pdfIn PDF document text
    • http://linde-erbach.de/images/free-roblox-accounts-with-robux-that-work-2021_GM431946152.pdfIn PDF document text
    • http://linde-erbach.de/images/coin-master-admin-free-spins_GM406889139.pdfIn PDF document text
    • http://linde-erbach.de/images/free-robux-sites-that-work_GM431946152.pdfIn PDF document text
    • http://linde-erbach.de/images/coin-master-unlimited-spin-link_GM406889139.pdfIn PDF document text
    • http://linde-erbach.de/images/how-to-get-free-robux-without-human-verification-2021_GM431946152.pdfIn PDF document text
    • http://linde-erbach.de/images/free-robux-no-verification-needed_GM431946152.pdfIn PDF document text
    • http://linde-erbach.de/images/minecraft-apk-free-download-016-0_GM479516143.pdfIn PDF document text
    • http://linde-erbach.de/images/free-minecraft-skins-pc_GM479516143.pdfIn PDF document text
    • http://linde-erbach.de/images/get-free-robux-2021_GM431946152.pdfIn PDF document text
    • http://linde-erbach.de/images/daily-free-spins-coin-master-2021_GM406889139.pdfIn PDF document text
    • http://linde-erbach.de/images/robux-gratis_GM431946152.pdfIn PDF document text
    • http://linde-erbach.de/images/master-8-ball-pool-free-coins_GM406889139.pdfIn PDF document text
    • http://linde-erbach.de/images/how-to-hack-roblox_GM431946152.pdfIn PDF document text
    • http://linde-erbach.de/images/coin-master-free-coin-and-spin-app_GM406889139.pdfIn PDF document text
    • http://linde-erbach.de/images/coin-master-free-spins-link-2021-today_GM406889139.pdfIn PDF document text
    • http://linde-erbach.de/images/coin-master-free-spins-2021_GM406889139.pdfIn PDF document text
    • http://linde-erbach.de/images/coin-master-apk-free-download_GM406889139.pdfIn PDF document text
    • http://linde-erbach.de/images/how-to-get-free-robux-easy-hack_GM431946152.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off00004566.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4566 25840 bytes
SHA-256: 03729523c72ee0f73e29873ddbf4c301fc59f0d9084fe45384ca11d80e515e52
font_01_sfnt_off00008009.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8009 19880 bytes
SHA-256: 6bc5cab104a17e5be196146aaeb40b5940258b3e295a46c016ac1ce7c3ec9493

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