Chief Engineer Aijaz Ahmad said the department has pressed men and machinery into service to restore the data and systems.
Officials of the department have lodged a complaint in this regard with the police’s cyber crime cell.
Meanwhile, the department has suspended its billing and other operations as the officials believe complete restoration of data would take around 10 days.
It has initiated an internal enquiry to find out the lacunae and officials said after discovering the cyber attack, all the network data lines were closed so that the hackers are stopped from accessing further data to expand their attack to other areas.
“Four of our servers have been compromised, which we are unable to access,” an official said.
It is reported that out of 101 servers of the department, 24 servers are under siege.