Kaseya said on Tuesday night that it had halted the planned reboot of its system
Company said that 'an issue was discovered that has blocked the release'
Came soon after CEO Fred Voccola vowed to resume services in 'coming hours'
Little-known IT firm was hit by ransomware attack from the REvil hacker gang
Gang claims it infiltrated a million businesses in the attack, but this is dubious
Kaseya says only 50 customers were breached, impacting 1,500 businesses