Malicious PDF — malware analysis report

Static analysis result for SHA-256 66f6183c84c6bb68…

MALICIOUS

PDF

42.8 KB Created: 2021-06-04 03:08:48 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-07-10
MD5: 66a827ede5cbc7ca0e1861a584a3db4e SHA-1: ef45bfac9b759fcdb080a1baa2ea542bb796f61a SHA-256: 66f6183c84c6bb68d75a18cb8f311ea7cae3fb961cb5a5f1b42f281612068581
260 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1071.001 Web Protocols

The PDF document contains multiple links to known malicious redirectors and impersonates brands like Amazon to trick users into clicking. The document body, though heavily obfuscated, contains references to 'freerubux' and 'game hack', aligning with the heuristic findings of a redirector lure and fake CAPTCHA. The primary malicious URL identified is https://netcdn.online/app/431946152/freerubux-game-hack, which is likely used to deliver a second-stage payload or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9874

Heuristics 7

  • PDF links to a 'free generator / game hack' redirector critical 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. CRITICAL on its own: the /app/<id>/<slug>-game-hack path shape is unambiguous scam infra, and the host rotates so a host-list match can't be relied on.
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.online/app/431946152/freerubux-game-hack.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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
  • 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/freerubux-game-hack In PDF document text
    • https://lib.unitri.ac.id/repository/pubg-uc-iraq_GM1330123889.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/how-to-get-stuff-that-cost-coins-free-mpe-master_GM406889139.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/free-roblox-website_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id/repository/coin-master-cards_GM406889139.pdfIn PDF document text
    • https://lib.unitri.ac.id/repository/coin-master-free-cards-and-spin-link_GM406889139.pdfIn PDF document text
    • https://lib.unitri.ac.id/repository/minecraft-bedrock-edition-download-pc-free_GM479516143.pdfIn PDF document text
    • https://lib.unitri.ac.id/repository/free-robux-without-offers_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id/repository/how-to-hack-roblox-games_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/how-to-get-free-coins-on-coin-master-hack_GM406889139.pdfIn PDF document text
    • https://lib.unitri.ac.id/repository/free-tiktok-followers-no-survey_GM835599320.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/how-to-hack-roblox-accounts-for-robux_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/coin-master-hack-android-root_GM406889139.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/how-to-get-free-robux-without-surveys_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/prison-life-roblox-hacks_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id/repository/download-hack-coin-master-apk_GM406889139.pdfIn PDF document text
    • https://lib.unitri.ac.id/repository/easy-roblox-today_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id/repository/tower-of-hell-roblox-hack_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/what-games-on-roblox-give-you-free-robux_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/how-to-hack-roblox-accounts-on-phone_GM431946152.pdfIn PDF document text
    • https://lib.unitri.ac.id//repository/mc-update_GM479516143.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_off00004f5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4F5F 23904 bytes
SHA-256: 21a3ccec6861c9d3241a4c0f2002153a0d9f9b768c0b896f6d893fcc07b845c9
font_01_sfnt_off00008612.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8612 17872 bytes
SHA-256: f4416bbc5f287efcbe31c7b4c704cc92a0ced0ddcdd2f5cfb5fb7d41fdf7fc1a

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