Some bitcoin users told me not to do transactions in these couple of days because hackers are active these days. I want to know is it true? or some kind of rumor? Anyone here who have faced such problem?
either they said it wrong or you misunderstood them.
there is nothing wrong with making transactions. for example if you had a bitcoin wallet in cold storage and have been safe so far, you are still safe. nothing has changed and hackers have been active all along.
the only thing different is when you are trying to use a new thing. in this case the bitcoin cash wallets. there are a lot of sleazeballs who will take this opportunity to scam. like by giving you a fake wallet with backdoor. just be careful what you download and where you are downloading it from.
the 48.5 bitcoin guy was a fool downloading a fake electrum wallet from a fake website!