The jury found him guilty of attempted murder of 93 people, the Sky News broadcaster reported.
Hassan arrived in the United Kingdom illegally in 2015, having crossed the Channel from the French city of Calais, and asked for asylum. Hassan claimed he was in fear of the Islamic State terrorist group (banned in Russia).
However, a witness heard by the jury, reportedly said that Hassan blamed the death of his parents on the West.
The bombing was the third attack in the British capital in 2017. In June, a trio of Daesh-associated Islamic extremists conducted a van-ramming attack on London bridge, killing eight before being shot dead by police.