Malicious PDF — malware analysis report

Static analysis result for SHA-256 dd79ef5f73310a44…

MALICIOUS

PDF

34.6 KB Created: 2021-07-05 05:04:17 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 9788ab0951334f5168a87c2304c8e5a8 SHA-1: f4a27c13500082f386add42047cb5477aa439710 SHA-256: dd79ef5f73310a44a2d143c7a473bccd0842107eaef5877c8ff5a3ad82137ecb
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by an ML classifier. 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 0.9980

Heuristics 5

  • 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.
  • 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 http://netcdn.tw/app/406889139/free-spin-coin-master-2021-link-game-hack PDF link annotation
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/cheats-for-roblox-jailbreak-money_GM431946152.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/roblox-2021-how-to-cheat-in-fencing_GM431946152.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/free-minecraft-printables_GM479516143.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/i-didnt-get-my-free-spins-in-coin-master_GM406889139.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/roblox-robux-free-promo-codes_GM431946152.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/codes-to-get-free-robux_GM431946152.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/roblox-walk-through-walls-cheat-engine_GM431946152.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/coin-master-daily-free-spins-2021_GM406889139.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/free-roblox-account-with-domino-crown-2021_GM431946152.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/free-robux-no-human-verification-or-survey-2021_GM431946152.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/how-to-hack-roblox-accounts-2021-april_GM431946152.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/minecraft-pe-apk-download_GM479516143.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/free-minecraft-severs_GM479516143.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/minecraft_GM479516143.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/ultimate-free-spins-coin-master_GM406889139.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/free-robux-images_GM431946152.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/coin-master-free_GM406889139.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/minecraft-free-download-pc_GM479516143.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/coin-master-hack-tool-download_GM406889139.pdfIn PDF document text
    • https://gzhi.govvrn.ru/uploads/ckfinder/userfiles/files/roblox-gift-card-free-codes_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_off000030a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x30A5 22536 bytes
SHA-256: feabccc50c229e6e6c7f3ba4e6fce5c2287e59bec8200d7bc2a31211786fc3c1
font_01_sfnt_off000062e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x62E8 18748 bytes
SHA-256: 87551c50e6d609f3c8aae9c53aca7d1ad4c281dc834da60ceb94801aa8be48ba