Windows 10 has a decent AntiVirus built right in the system, namely Windows Defender. To get the details about the status of it, simply use this cmdlet to find out.
Get-MpPreference
However, if you have a 3rd party AntiVirus installed, Get-MpPreference isn’t good enough anymore as it only works and reveals information about Windows Defender. Use the following instead:
Get-CimInstance -Namespace root/SecurityCenter2 -Classname AntiVirusProduct

To use it on a remote computer, add -ComputerName switch along with the command.
Get-CimInstance -Namespace root/SecurityCenter2 -Classname AntiVirusProduct -ComputerName $computer
Digging it a bit deeper, how to find out the status of the installed AntiVirus software?
Encoded in ProductState property are a number of additional pieces of information, such as whether the AV engine is operational, and is using the up-to-date data signatures. To decipher the meaning of this information, refer to this post that demonstrates how to use PowerShell’s new support for enumerations.
To put all together,
# define bit flags
[Flags()] enum ProductState
{
Off = 0x0000
On = 0x1000
Snoozed = 0x2000
Expired = 0x3000
}
[Flags()] enum SignatureStatus
{
UpToDate = 0x00
OutOfDate = 0x10
}
[Flags()] enum ProductOwner
{
NonMs = 0x000
Windows = 0x100
}
# define bit masks
[Flags()] enum ProductFlags
{
SignatureStatus = 0x00F0
ProductOwner = 0x0F00
ProductState = 0xF000
}
# get bits
$infos = Get-CimInstance -Namespace root/SecurityCenter2 -ClassName AntiVirusProduct -ComputerName $computer
ForEach ($info in $infos){
[UInt32]$state = $info.productState
# decode bit flags by masking the relevant bits, then converting
[PSCustomObject]@{
ProductName = $info.DisplayName
ProductState = [ProductState]($state -band [ProductFlags]::ProductState)
SignatureStatus = [SignatureStatus]($state -band [ProductFlags]::SignatureStatus)
Owner = [ProductOwner]($state -band [ProductFlags]::ProductOwner)
}
}
The result is pretty nice.

What would be more useful is to run the script through a whole network to assess how AntiVirus software is deployed and maintained in your network.