The attack began at 10 a.m. Sunday, the company said in a statement to investors early Monday.
"We had a tough day but we were able to overcome the attack thanks to our customers and partners."
A company spokesperson told VnExpress Monday that it has resolved the issues and is in the process of resuming trading, though it could take some time.
As of 10:51 a.m. Monday, almost two hours after trading began for the day, VNDirect’s website and trading system were not accessible. Investors could not trade on their smartphone either.
VNDirect, established in 2006, ranked third last year in the number of accounts, accounting for 7.01% of the total and only behind SSI Securities Corp and VPS Securities.