I've heard bad episodes from every commercial AV maker.
My complaint since Microsoft delivered Defender then Security Essentials is that, when virus-warnings might pop up, Microsoft doesn't display their precise product's name in the Active Window Title Textbar.
If MS Security Essentials detects a threat, the dialog box's Active Title doesn't read "Microsoft Security Essentials" but some other vague Microsoft AV name.
Just like hijacker dialog boxes do - "Windows Anti-Virus" looks AS authentic as Microsoft's own Active-Window title spellings, yet that was an early Hijacker Website's attack method.
How could most users detect Real vs. Fake when their real Microsoft products refuse to use their real and specific names?!! Answer: users CANNOT.
And one of the worst aspects is that a careful user may seldom see a virus alert, so after months or a year or more with "Microsoft Defender/Security Essentials" protecting them, they see a vague "Windows Anti-Virus Alert" titled dialog box and what's the first reaction?!! "SAVE ME!! PROTECT ME!!"
And kablooey - the virus has been invited in and uses that User's Rights to disable any and everything else.
And Microsoft merrily says, "That calibre of User has the rights to injure or destroy the Windows installation."
If MS would use Precise & Exact Active Window Spellings and THEN install an interrogator-code that says, "If these words are used by any other Dialog's Title, check the IP address against Microsoft's authorized ones..." then most hijackers would be a far lessened threat.
But since Microsoft programmers apparently can't spell or won't use precise and exact names, then the consumers are left at the mercy of any willy-nilly hijack threat.
Common Sense is our best defense but Microsoft helps to undermine even THAT solution.