A lot is discussed about ever changing threat landscapes facing the IT world BUT from digital investigators the problems are usually always ever down to the following: -
1. Lack of Anti Virus
2. Lack of patching on Systems
3. User Error and Lack of Training.
4.Phishing attacks - linking to 3 above.
5. Running as Administrator of your machine all the time.
In short - it's the basics which the majority of people know and which aren't adhered to is what trips people up!