For quite a while now Microsoft has been releasing bug fixes once a month, on the second Tuesday of the month. Techies refer to this as Patch Tuesday.
They used to release bug fixes as needed but that generated too much bad publicity - there were frequent high profile bug fixes. Don't think it's the publicity? Then why were bug fixes renamed "patches" and then renamed again to "updates".
Now the bad guys have learned to use Microsoft's avoidance of bad publicity to their benefit. They start exploiting newly found bugs the day after Patch Tuesday. This way, they get a full month to wreak havoc before Microsoft issues a fix. At least a month, sometimes more. While the cat's away the mice will play.
- The bad guys exploit bugs for a month
- Microsoft limits bad publicity to one day a month
It's good to be a monopoly.