Smb relay attack hacktricks

1. What is SMB relay attack?
2. Is LLMNR the same as mDNS?
3. What is mDNS spoofing?
4. What is Llmnr poisoning attack?
5. Is SMB an exploit?
6. Can a hacker still damage a network using SMB?
7. Is LLMNR still used?
8. Is it safe to disable mDNS?
9. Should I disable LLMNR?
10. Is mDNS a security risk?
11. Is mDNS UDP or TCP?
12. How does relay attack work?
13. What does SMB mean in cyber security?
14. Which vulnerability does SMB Relay exploit?
15. How does SMB vulnerability work?
16. What are examples of relay attack?
17. Can thieves bypass immobilizer?

What is SMB relay attack?

SMB Relay Attack is a type of attack which relies on NTLM Version 2 authentication that is normally used in most companies. Unfortunately, when we are listening to what is going on in the network, we're able to capture a certain part of the traffic related to the authentication and also relay it to the other servers.

Is LLMNR the same as mDNS?

Both implementations are very similar. Apple's Multicast DNS (mDNS) is published as a standards track proposal RFC 6762, while Microsoft's Link-local Multicast Name Resolution (LLMNR) is published as informational RFC 4795.

What is mDNS spoofing?

Description​ The configuration of the MDNS services allows an attacker to spoof IP addresses effectively hijacking them or causing a denial-of-service. Alternatively, due to a lack of certain security measures, it is possible to intercept requests to mDNS services and obtain information about the connected devices.

What is Llmnr poisoning attack?

In a network, if a machine tries to resolve a particular host and DNS fails to do so, the machine will communicate with other machines in the network using the LLMNR and ask if anyone knows the particular hosts.

Is SMB an exploit?

The SMB vulnerability can let an unauthorized attacker to run any code as part of an application. According to the Microsoft advisory, “To exploit the vulnerability against an SMB Server, an unauthenticated attacker could send a specially crafted packet to a targeted SMBv3 Server.

Can a hacker still damage a network using SMB?

SMBv1 has a number of vulnerabilities that allow for remote code execution on the target machine. Even though most of them have a patch available and SMBv1 is no longer installed by default as of Windows Server 2016, hackers are still exploiting this protocol to launch devastating attacks.

Is LLMNR still used?

It is also implemented by systemd-resolved on Linux. LLMNR is defined in RFC 4795 but was not adopted as an IETF standard. As of April 2022, Microsoft has begun the process of phasing out both LLMNR and NetBIOS name resolution in favour of mDNS.

Is it safe to disable mDNS?

Warning! Disabling mDNS can have unexpected negative consequences. Wireless screen sharing/mirroring in conference rooms may stop working. Accessing printers may break.

Should I disable LLMNR?

The number one way to protect a system from being exploited is to disable LLMNR and NBT-NS. Responder uses these two protocols in order to grab password hashes from other systems on the network. Ensure that both of these protocols are disabled, since Windows defaults to using the other when the other fails/is disabled.

Is mDNS a security risk?

It is not a security risk itself, but can help.

Is mDNS UDP or TCP?

It uses IP multicast User Datagram Protocol (UDP) packets, and is implemented by the Apple Bonjour and open source Avahi software packages, included in most Linux distributions.

How does relay attack work?

How does a relay attack work? A relay attack usually involves two people working together. One stands by the targeted vehicle, while the other stands near the house with a device that can pick up a signal from the key fob. What's more, some devices can pick up a signal from over 100 metres away.

What does SMB mean in cyber security?

What is the Server Message Block protocol? The Server Message Block protocol (SMB protocol) is a client-server communication protocol used for sharing access to files, printers, serial ports and other resources on a network. It can also carry transaction protocols for interprocess communication.

Which vulnerability does SMB Relay exploit?

The SMB Relay attack abuses the NTLM challenge-response protocol. Commonly, all SMB sessions used the NTML protocol for encryption and authentication purposes (i.e. NTLM over SMB).

How does SMB vulnerability work?

SMB vulnerabilities have been around for 20+ years. In general, most cyber-attacks involving SMB do not occur because an enterprise failed to procure an expensive tool or application, but rather because there was a failure to implement best practices surrounding SMB.

What are examples of relay attack?

In contrast, in a relay attack an attacker intercepts communication between two parties and then, without viewing or manipulating it, relays it to another device. For example, a thief could capture the radio signal from your vehicle's key fob and relay it to an accomplice who could use it to open your car door.

Can thieves bypass immobilizer?

Thieves listen in on the signals between your car and the locking system and with the help of a little technology in half an hour they can disarm the immobiliser, taking away one of the vital security barriers stopping them from stealing your vehicle.