Malicious PDF — malware analysis report

Static analysis result for SHA-256 665118380e5fbe7a…

MALICIOUS

PDF

44.3 KB Created: 2021-06-03 10:52:15 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 61d7832f2d1aed781747567186748e39 SHA-1: 5d79699397cc6dd951b701f938e58c9a971aa9d1 SHA-256: 665118380e5fbe7a0ee085441f5a5b35d126b0cf5a489156e3840718582e7405
242 Risk Score

Malware Insights

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

This PDF document employs a common lure of "Robux Generator No Human Verification" and impersonates the UPS brand to trick users into clicking malicious links. The document contains a large number of external links, many of which are SEO-optimized PDF links, suggesting a link farm or SEO poisoning tactic. The ML classifier also flagged this PDF with high confidence, indicating malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9865

Heuristics 8

  • 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
  • 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/robux-generator-no-human-verification-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
  • 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/robux-generator-no-human-verification-game-hack PDF link annotation
    • https://ifef.es/ckfinder/userfiles/files/coin-master-online-free-spin_GM406889139.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/how-to-get-free-robux-hack_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/how-to-hack-roblox-accounts-on-phone_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/how-to-get-free-coins-on-coin-master_GM406889139.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/free-dominus-roblox_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/free-robux-no-verification-2021_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/minecraft-windows-10-edition-hacked-client_GM479516143.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/why-pokemon-go-free-download_GM1094591345.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/how-to-get-free-pet-food-on-coin-master_GM406889139.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/coin-master-free-spins-apple_GM406889139.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/free-roblox-followers_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/free-robux-no-survey_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/daily-coin-master-link_GM406889139.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/daily-free-spin-coin-master-link_GM406889139.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/free-spins-coin-master-2021-glitch_GM406889139.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/roblox-robux-hack_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/robuxy-com-free-robux_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/get-free-robux-without-doing-anything_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/how-to-get-free-robux-2021_GM431946152.pdfIn PDF document text
    • https://ifef.es/ckfinder/userfiles/files/add-robux_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
stream_004_off0000511b.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x511B 25244 bytes
SHA-256: 20ccdf192859b352b41d458247e16a254c10713cc6fa80932da70cc6daf35e33
font_01_sfnt_off0000894a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x894A 18696 bytes
SHA-256: 8eb9ce3d194ebd03f4b6150cacde388236e8b741187c4105b43b6f56dc8e9421