A sophisticated attack will have been very well planned and resourced. If the attackers have gained access to your environment they will be performing reconnaissance and planning the attack. Their objective will be to deny you access to your systems and remove your ability to recover.
A common attack is ransomware that affects one or more platforms. A ransomware attack on Windows will usually propagate companywide with Active Directory being a prime target as this is used in most organisations for authentication. Linux ransomware is becoming more prevalent as attackers know most companies systems rely on Linux and protection for Windows is becoming stronger.