29 October 2017
WannaCry, NotPetya, and now: Bad Rabbit. The good news is that Bad Rabbit isn’t spreading as fast as WannaCry and NotPetya. According to a DARKReading report from October 25th the outbreak appears to die down already.
The bad news is, that it happened again. Like the White Rabbit in Alice’s Adventure in Wonderland, IT departments seem to mutter only “Oh dear! Oh dear! I shall be too late!”, instead of increasing the security baseline of their company networks.
Bad Rabbit uses similar techniques as WannaCry and NotPetya for spreading in the networks:
Open SMB shares, Mimikatz alike ways to dump credentials from the affected systems, a hardcoded list of credentials, … For more technical details see this post from Malwarebytes Labs.
The methods to avoid this are well-known and easy and cheap to implement:
- Run a user awareness campaign.
- Reduce the number of users and administrators working with permanent administrative privileges to zero. This is a leadership task!
- Apply the measures to mitigate Pass-the-Hash attacks to all Windows systems and networks.
- Limit the functionality of technical users to local systems and the lowest possible privileges. Use individual passwords, eliminate default passwords.
- Review all firewall rules. Question every required connection. Limit the use of the SMB protocol as far as possible. Eliminate the use of unsecured protocols as far as possible. Patch the systems at the endpoints of firewall rules.
The above list is not exhaustive, but if implemented, the attacker’s ability to explore the network is clearly reduced.
It appears to me, that everyone is waiting for Windows 10 to solve some of the issues. This however is the wrong approach. Windows 10 cannot be introduced with a big bang. In particular in the production, lab, and building automation domain, it will take a few years until we can shutdown Windows XP/7 completely. And during this years, our networks are at risk.
With this, there is no time to lose. The White Rabbits returns.
Have a great week.