As you can imagine I see a lot instances where customers have been subjected to a virus, malware or adware attack and this made me consider my own practises and the outcomes should I be infected sometime.
I was quite happy with small transactions such as small bills, transfers to the children's accounts and reimbursing friends as one can always check that the first expected payment has gone through and you know that subsequent payments will continue thereafter.
Consider the large transaction such as paying for a car though. Don't take it as read you are paying to the correct account. Most sellers require cash on the day before handing over any keys so how do you test the money will arrive in the intended account. I heard on the radio the other day where a lady had parted with £12,000 in the purchase of a van to the wrong account as her emails were being monitored by hackers and they knew she was about to pay a large amount. They were able to intercept emails and insert their own with false payment account details. One way would be to transfer £1 pound initially and confirm with the rightful recipient that the money had arrived. Most banking transactions take place immediately so it won't be that long to check - besides it's a small price to pay for the amount you could lose. Warning your bank that a large payment will be made is advisable.
Someone can correct me here but I believe that once a payment has been made then it is very difficult for the bank to recover the money as they are unable to recind an instruction to pay. It is also likely that once transferred the money would have been withdrawn very quickly.