Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cf044e4c90caa7…

MALICIOUS

PDF

42.7 KB Created: 2021-05-20 02:29:55 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-01
MD5: c7c751390ab9afa05ac9968fc0fdcce8 SHA-1: 0d9d1c4d26157907ab3cc0c0ebf1e44645d9a821 SHA-256: 21cf044e4c90caa7b75bf54f24cf956beb661ca024f2acf71ce01e6df7cb610c
162 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 brand-impersonation credential phishing and a fake-CAPTCHA lure. The file 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 0.9971

Heuristics 6

  • 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
  • Brand-impersonation credential phishing lure high SE_BRAND_CREDENTIAL_PHISH
    Document impersonates a well-known consumer brand and uses account-security / verification language ('unusual activity', 'account on hold', 'verify your account') to steer the reader to a credential-harvesting link. Corroborated by: call-to-action link host does not match the impersonated brand: https://netcdn.xyz/app/431946152/free-robux-without-verify-game-hack.
  • 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/free-robux-without-verify-game-hack PDF link annotation
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/coin-master-heaven-daily-free-spins-and-coins-links_GM406889139.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/real-coin-master-free-spins_GM406889139.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/hack-coin-master-apk-2021_GM406889139.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/free-robux-survey_GM431946152.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/coin-master-hacks-xyz_GM406889139.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/coin-master-redeem-code-free_GM406889139.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/oprewards-robux_GM431946152.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/free-coin-master-spin-app_GM406889139.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/can-i-get-robux-for-free_GM431946152.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/free-spins-and-coins-coin-master_GM406889139.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/easy-ways-to-get-free-robux_GM431946152.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/how-to-get-free-robux-easy_GM431946152.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/how-to-get-free-robux-2021_GM431946152.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/coin-master-hack-mod-apk-free-download_GM406889139.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/minecraft-fly-hack_GM479516143.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/grabpoints-robux_GM431946152.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/free-robux-no-verification-no-download-2021_GM431946152.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/minecraft-bedrock-server-hosting-free_GM479516143.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/wurst-commands_GM479516143.pdfIn PDF document text
    • http://www.nlcitychurch.org.hk/upload/userfiles/files/free-roblox-accounts-2021_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_off00004b63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4B63 24300 bytes
SHA-256: e13b3f15952cd6a5015fc75e9825fa6698566e458544850344970843a5a7cb85
font_01_sfnt_off000082ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x82AB 18916 bytes
SHA-256: 511fbd4ba16aacf51779f52d01f2fc894dffaba514ce449b994b41b42032bc0e

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