Have you tried using the official ( http://developer.android.com/tools/help/adb.html ) instead? Is there something different in the xda variant that would want to make you install it instead of the official?
mempodroid is a known exploit to gain root privileges on android. It has been packaged in its original form to aid in rooting some devices. The antivirus is correct in identifying it, but it does not affect Windows environments, and is not dangerous or harmful when used for escalating privileges on Android to gain root.
Well if it is indeed a “known exploit to gain root privileges” as the poster states, then the detection is valid. It is malicious in a way that gives your device more privileges through exploitation, which can be used for both good and bad purposes.