However, there was no loss of the billing data as a backup was already available with the Uttar Haryana Bijli Vitran Nigam (UHBVN), the official said, adding that the billing of consumers was also not affected.
"There is no business loss and there is continuity in the business," he said.
The cyber attack took place on March 21 on the AMR through which the billing of about 4000 Industrial consumers is being done, he said.
The system is installed, operated and managed by Tata Consultancy Services Ltd. (TCS) since 2011.
Immediately after the attack the complete system study was carried out by the concerned officers, cyber expert as well as other IT experts, the spokesman said.
"The database was found encrypted and the backup ofencrypteddatabase was also taken for further retrieval," he said.
An FIR into the incident has been lodged, the official informed.
Steps to phase out the present system were take well before by the Nigam. The system will be replaced by the latest, robust and technologically advanced system on cloud services which shall be operational by the end of May 2018, he said.
"The billing of 4000 consumers has already started functioning normally", he added.
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