Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7983ccae266f07d…

MALICIOUS

PDF

49.4 KB Created: 2021-05-14 09:29:21 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 3f0b8386d7e0b53bbdb373f1432a2f7e SHA-1: 230fc912551978525ba630adf80eeac1e58998c3 SHA-256: b7983ccae266f07d3b236c95404398190216d84d0fd13b85419cb85dc9b9d130
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 0.8642

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/406889139/coin-master-attack-madness-hack-game-hack PDF link annotation
    • https://vireco.store/ckfinder/userfiles/files/coin-master-free-link-spin_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/free-robux-no-verification-2021_GM431946152.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/how-to-get-free-robux-without-verification-2021_GM431946152.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/minecraft-education-edition-free-download_GM479516143.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/free-mods-for-minecraft-pe_GM479516143.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/free-robux-without-survey_GM431946152.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/coin-master-free-spins-today-39_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/free-spin-link-coin-master_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/completed-coin-master-hack_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/free-coin-master-spins_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/minecraft-games-free-to-play-online_GM479516143.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/how-to-get-free-robux-without-downloading-apps-2021_GM431946152.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/free-robux-sites-that-work_GM431946152.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/coin-master-hack-tool_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/coin-master-free-gift-cards_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/best-free-minecraft-server-hosting-reddit_GM479516143.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/coin-master-free-spins-link_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/coinmaster-fan-page_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/daily-free-spins-on-coin-master_GM406889139.pdfIn PDF document text
    • https://vireco.store/ckfinder/userfiles/files/roblox-hack-generator_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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off00004ab9.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4AB9 24052 bytes
SHA-256: a2753743226a0bd7d728bb0d6a45f997704195b3aed136ddaaf0acc035a71687
font_01_sfnt_off0000815e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x815E 2840 bytes
SHA-256: 3fb127b764b9d10f5525bc4de5ec8316de704409ccb0cf21cff3ad8a30d11676
font_02_sfnt_off00008b0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8B0A 8676 bytes
SHA-256: e06aca5f85e50ae6cefda302c5299c18ab6d27c174f74f0bb0ee8efa7ccb4468
font_03_sfnt_off00009f95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9F95 17888 bytes
SHA-256: f7a53a65286f7c98125d4d45247e8746e7e120bffcc9c77c9c81cd5151e0f106

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