Ethereum Classic has a proactive team

[Munareal]

Ethereum Classic underwent a 51% attack or double-spend attack on January 5, 2019. The attack resulted in 88,500 ETC (roughly $450,000 at the time) being stolen from the ETC blockchain.

To prevent this from ever happening again, the newly appointed ETC Core team has developed an alert system that surveils the level of threat to Ethereum Classic’s blockchain. The system looks for suspicious activity based on block analysis and block propagation patterns.

Anyone can access the tool and view its status at ETCStatus.Live.
https://etcstatus.live/