Malicious redirection, track down the cause and resolve, FIXED BUDGET INR 1050 ONLY No Advance payment

Hi there, on our website [login to view URL] we have seen some malicious redirection which are happening only on mobile device whenever anyone visit our website for the first time , this is been happening since last 2-3 weeks if you revisit the website there will be no redirection , we want you to track down the issue causing such redirection, remove the same at earliest. Fixed budget : INR 650 only, no advance payment, Start your bid with UTM else your bid will be ignored for bot/auto bidding and same will be reported