Malicious PDF — malware analysis report

Static analysis result for SHA-256 21fdd34775a78216…

MALICIOUS

PDF

47.2 KB Created: 2021-06-08 16:05:18 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 517b694d2873c763cea1ef18408ae522 SHA-1: 1d4e8e43c29a892751b7c03f2f9c1981cd5eb515 SHA-256: 21fdd34775a78216861b8698bedd027e5b77a2d071cb6be537a2f3ae0650a6d5
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous links to external websites, many of which are disguised as generators or hacks for popular games like Robux and Coin Master. The heuristic 'PDF_SEO_LINK_FARM' indicates a large number of these links, suggesting a link farm designed to drive traffic or potentially host malicious content. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9769

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 https://netcdn.tw/app/431946152/how-to-get-free-robux-on-ipad-air-game-hack PDF link annotation
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/coin-master-free-spins-link-no-verification-2021_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/coin-master-free-spins-no-human-verification_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/free-tiktok-followers-without-verification_GM835599320.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/coin-master-daily-free-spins-2021_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/freespins-coin-master_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/free-roblox-promo-codes-for-robux_GM431946152.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/free-coins-coin-master-link-2021_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/free-robux-that-actually-works-2021_GM431946152.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/free-spins-for-coin-master_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/how-to-get-minecraft-for-free-on-android-device_GM479516143.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/coin-master-free-spin-and-coin_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/coin-master-free-spins-links-2021_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/pop-slots-free-vegas-casino-slot-machine-game-coin-master_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/how-to-get-hacks-on-minecraft_GM479516143.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/free-robux-generator-codes_GM431946152.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/coin-master-online-hack_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/roblox-got-talent-piano-hack_GM431946152.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/get-free-spins-for-coin-master_GM406889139.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/roblox-mobile-hack_GM431946152.pdfIn PDF document text
    • https://www.ktcart.co.in/uploaded_files/userfiles/files/how-to-hack-any-roblox-account_GM431946152.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_004_off000050e3.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x50E3 24660 bytes
SHA-256: c074f81c2911eed87faea19d22e478eafea411a302d454a4d79842252f455acb
font_01_sfnt_off0000899b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x899B 2844 bytes
SHA-256: baad2f3f6808f4af03fa9398e38c580c8d846f7f773a947d8cc1f39b2753d31a
font_02_sfnt_off0000935d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x935D 18980 bytes
SHA-256: 66537b2c3e275a77eea7235f39a17d3a92e9442005f75a5c408d35d5f9990e74