This is a known issue with Kaspersky. We’ve been in communication with them - athough it’s been slow - to get Brave whitelisted on their end. For now, a Community member (@MediaBird) has a workaround to whitelist Brave locally so you can download/install Brave without issue. Link here:
https://community.brave.com/t/auto-updater-for-dev-builds-is-detected-as-trojan-by-kaspersky-antivirus/34917/7?u=mattches