Malicious PDF — malware analysis report

Static analysis result for SHA-256 82cb2b5fd614bdd7…

MALICIOUS

PDF

45.3 KB Created: 2021-06-03 10:00:37 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-04
MD5: e4e8042f51ea955750cc4e9e26548ec0 SHA-1: 5d19041e13d15def983b4ec2e000cb3c7b5b48a1 SHA-256: 82cb2b5fd614bdd781ebf8816018aa26a5101f7ff7b1bc67ca86491ce0b67276
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 0.9864

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.online/app/431946152/bloxland-earn-free-robux-game-hack PDF link annotation
    • http://library.umla.ac.id//repository/how-to-get-free-unlimited-robux_GM431946152.pdfIn PDF document text
    • http://library.umla.ac.id//repository/coin-master-rewards-2021_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id//repository/how-can-i-get-free-spins-on-coin-master_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id/repository/coin-master-free-spins-cash_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id//repository/pop-slots-free-vegas-casino-slots-machine-game-coin-master_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id//repository/roblox-free-robux-generator_GM431946152.pdfIn PDF document text
    • http://library.umla.ac.id/repository/sites-for-free-spins-for-coin-master_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id/repository/minecraft-windows-10-edition-free-download_GM479516143.pdfIn PDF document text
    • http://library.umla.ac.id//repository/pubg-uc-to-pkr_GM1330123889.pdfIn PDF document text
    • http://library.umla.ac.id//repository/free-apk-mods-coin-master_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id//repository/coin-master-hack-iosgods_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id/repository/free-minecraft-hosting-24-7_GM479516143.pdfIn PDF document text
    • http://library.umla.ac.id//repository/coin-master-cards-free_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id/repository/coin-master-free-spin-and-coin-link-today_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id/repository/coin-master-hack-spins-android_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id//repository/free-robux-com_GM431946152.pdfIn PDF document text
    • http://library.umla.ac.id//repository/how-to-get-minecraft-for-free-on-laptop_GM479516143.pdfIn PDF document text
    • http://library.umla.ac.id//repository/coin-master-free-spin-and-coin_GM406889139.pdfIn PDF document text
    • http://library.umla.ac.id//repository/robuxy-com-free-robux_GM431946152.pdfIn PDF document text
    • http://library.umla.ac.id//repository/coin-master-unlimited-spin-apk-free-download_GM406889139.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
stream_004_off0000514e.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x514E 25860 bytes
SHA-256: 682a33718b0bfcd22bb8199a1fcd34f64a0fd8909521b9ba9ec8fd191dbcec58
font_01_sfnt_off00008df5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8DF5 18492 bytes
SHA-256: fc87a0e838629003b9f405fc2c8429e0a8062f092f4b8629944097aaaaee9c58

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