Malicious PDF — malware analysis report

Static analysis result for SHA-256 a53f5092e024a9d6…

MALICIOUS

PDF

44.7 KB Created: 2021-05-10 20:48:38 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-01
MD5: b69d5a13a2c8340353395fe2a20b51b0 SHA-1: e4308b5de50b98e740da7e3832e490b33911d28e SHA-256: a53f5092e024a9d62c9e017c0c89fb3e9e77d9319dcc37cfd67c7ebf6e081bef
182 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. It uses a fake-CAPTCHA lure. The file embeds a large number of external links characteristic of an SEO link farm, routes users through malicious redirector infrastructure and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9632

Heuristics 6

  • 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
  • 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/rbxcity-free-robux-game-hack PDF link annotation
    • http://lib.mbp.ac.id/repository/coin-master-hack-2021-no-survey_GM406889139.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/free-robux-without-downloading-anything_GM431946152.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/how-to-get-free-robux-without-paying_GM431946152.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/minecraft-noob-vs-pro-vs-hacker_GM479516143.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/minecraft-complete-handbook_GM479516143.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/roblox-army-free-robux_GM431946152.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/how-to-change-username-on-roblox-for-free_GM431946152.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/win-free-robux_GM431946152.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/roblox-games-com-free_GM431946152.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/free-spin-link-for-coin-master-haktuts_GM406889139.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/free-robux-no-download_GM431946152.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/hack-coin-master-without-root_GM406889139.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/how-to-play-minecraft-with-friends-for-free_GM479516143.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/plug-toolbox-for-minecraft-free-ios_GM479516143.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/how-do-you-install-minecraft-for-free_GM479516143.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/minecraft-java-free-trial_GM479516143.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/minecraft-games-to-play-for-free_GM479516143.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/robux-hack-generator_GM431946152.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/united-gaming-net-coin-master-hack_GM406889139.pdfIn PDF document text
    • http://lib.mbp.ac.id/repository/official-coin-master-free-spins_GM406889139.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off000047c1.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x47C1 25128 bytes
SHA-256: 4d684050504f0d0a6119a9ffe15eeb56b80fe55890ab41a6b5b6123b9e244fb7
font_01_sfnt_off000081de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x81DE 2832 bytes
SHA-256: 77ae1c4cffa647a8fd533dfa4102e94364989f9e80b9cd131876e9d1005899a2
font_02_sfnt_off00008b8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8B8F 18420 bytes
SHA-256: f6fda3bfe323f9f0676c079c6b9141a3a072b0621584b37e36c0c9937e592518

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