Talktalk Telecom Group is the latest ISP to be attacked by Mirai software

A cyber attack on Britain's Talktalk Telecom Group PLC broadband affected "a small number of customer routers" on Thursday, the company said in a statement. "Along with other Internet Service Providers in the UK and abroad, we are taking steps to review the potential impacts of the Mirai worm", Talktalk said, adding it has put additional controls in place.Mirai is a malicious software which in October cut off access to some of the world's best known websites, including Twitter and Spotify. A cyber attack affecting some types of routers hit around 100,000 of Britain's Post Office broadband customers on Sunday, Post Office said in a statement on Thursday.The company added, "although this did result in service problems... no personal data or devices have been compromised. We have identified the source of the problem and implemented a resolution."On Tuesday the German government and commercial security experts said hundreds of thousands of Deutsche Telekom AG customers suffered internet outages as a result of a worldwide attempt to hijack routing devices.  Cyber attacks all over the world are increasing in intensity and complexity as according to cyber security firms Shamoon, the destructive computer virus that four years ago crippled tens of thousands of computers at Middle Eastern energy companies, was used two weeks ago to attack computers in Saudi Arabia.With inputs from Reuters