In the last few days, when I try to go to a site I usually use (in the last case, Verizon's "your documents" site), MalwareBytes Anti-Exploit Free pops up a "malicious site blocked" for downloadopensoftware.com, and possibly one other, but I remember this one. I'm not noticing any other effects on my system. Popups happen in both Chrome 52.0.2743.116 and Firefox 47.0.1. I almost never use Internet Explorer. I've found advice that recommends using the control panel to uninstall the bad software but nothing called downloadopensoftware is installed on my system.
My system: Windows 7 Pro 64 bit, patched to date
Security software: Windows Firewall; BitDefender Free 188.8.131.529; Malwarebytes Pro 184.108.40.2063; MalwareBytes Anti-Exploit 1.08.1.272 (was free but I just paid for it as free doesn't seem to log incidents)
I normally run a MalwareBytes Hyper scan daily (ran this morning, found nothing), and a Threat scan weekly (tomorrow; I'm running it right now, and it is checking for rootkits).
I thought this system was pretty secure; all these programs run all the time. And since I'm not seeing effects but the blocking popups from MalwareBytes Anti-Exploit, they seem to be working. But if I'm getting blocks, I must be getting undercover requests from this critter; I'd like to get rid of it. I know about your instructions for getting rid of adware and viruses and will go through it, would appreciate advice.
But I'd like to know if I should modify my security in some way. I've preferred the free anti-virus software for some years and would like to stay with it, but I'm open to advice.