Luring attackers towards deception servers
Endpoints in a computer network create connections to a deception server without sending any payload data. The connections create records of the connection on the endpoints, by which an attacker accesses the deception server. Received packets that include payload data are determined to be unauthorized. The deception server acquires IP addresses in various VLANS and provides these IP addresses to the endpoints over a secure channel. The connections from the endpoints to the deception server are not performed on the secure channel. IP addresses acquired by the deception server are not assigned to an interface. Instead, NAT is used to route packets including the IP addresses to various engagement servers. Each IP address is assigned a unique hostname in order to appear as multiple distinct servers. The deception server further generates broadcast traffic to generate other records that may be used to lure an attacker to the deception server.
1. A method comprising:
receiving, by a server system, a first connection request from an agent executing on a first computer system, the agent programmed to generate the first connection request without transmitting any payload data;
in response to the first connection request, establishing, by the server system, a first connection with the first computer system without receiving any payload data over the first connection such that no connection table entry is created on the server system but a connection table entry is created on the first computer system;
receiving, by the server system, a second connection request from a second computer system;
in response to the second connection request, establishing, by the server system, a second connection with the second computer system;
receiving, by the server system, one or more packets over the second connection, the one or more packets including payload data; and
in response to receiving the payload data in the one or more packets, determining that the second computer system is engaged in malicious activity whereas the first connection over which no payload data is transmitted is not determined to be a result of malicious activity;
wherein the method further comprises:
acquiring, by the server system, a plurality of unassigned internet protocol (IP) addresses without assigning the unassigned IP addresses to an interface;
performing network address translation to route packets referencing the plurality of unassigned IP addresses to the server system;
transmitting, by the server system, the plurality of unassigned IP addresses to the first computer system over a secure channel, the first connection request not being received over the secure channel;
wherein the first connection request is addressed to one of the plurality of unassigned IP addresses.
2. The method of claim 1 , wherein the only communication with the first computer system is no more than a TCP (transmission control protocol) handshake; and
wherein the one or more packets include more than a TCP handshake.
3. The method of claim 1 , further comprising:
assigning, by the server system, a unique host name to each unassigned IP address of the plurality of unassigned IP addresses; and
responding, by the server system, to hostname requests addressed to the each unassigned IP address of the plurality of unassigned IP addresses with the unique host name assigned to the each unassigned IP address.
4. The method of claim 3 , further comprising for each unassigned IP address of the plurality of unassigned IP addresses:
transmitting, by the server system, simulated traffic referencing the each unassigned IP address and the unique host name assigned to the each unassigned IP address.
5. The method of claim 4 , wherein the simulated traffic is at least one of a host announcement and initiation of a registration process.
6. The method of claim 4 , wherein the simulated traffic comprises a broadcast message according to at least one of:
NetBIOS (basic input output system) Name Service (NBNS) protocol using the unique host names;
Link-Local Multicast Name Resolution (LLMNR) protocol using the unique host names; and
multicast domain name resolution (mDNS) protocol using the unique host names.
7. The method of claim 1 , further comprising:
for each unassigned IP address of the plurality of unassigned IP addresses assigning, by the server system, a grouping of services to the each unassigned IP address, the grouping of services being a subset of all services implemented by the server system;
receiving, by the server system, for a first IP address of the plurality of unassigned IP addresses, a first request for a first service not included in the grouping of services assigned to the first IP address; and
in response to receiving the first request, transmitting, by the server system, a response to the first request indicating that the first service is not available even though the first service is available on the server system.
8. A server system comprising one or more processing devices and one or more memory devices, the one or more memory devices storing executable code effective to cause the one or more processors to:
receive a connection request from a computer system;
in response to the connection request, establish a connection with the computer system;
if one or more packets are received over the connection that include payload data, determine that the computer system is engaged in malicious activity and make an entry in a connection table; and
if the no packets are received over the connection that include payload data, do not determine that the computer system is engaged in malicious activity and make no entry in in the connection table for the connection;
wherein the executable code is further effective to cause the one or more processors to:
acquire a plurality of unassigned internet protocol (IP) addresses without assigning the unassigned IP addresses to an interface;
perform network address translation to route packets referencing the plurality of unassigned IP addresses to the server system;
transmit the plurality of unassigned IP addresses to the computer system over a secure channel, the connection request not being received over the secure channel;
wherein the connection request is to one of the plurality of unassigned IP addresses.
9. The server system of claim 8 , wherein the executable code is further effective to cause the one or more processors to determine that the computer system is engaged in malicious activity in response to any communication from the computer system other than a TCP (transmission control protocol) handshake.
10. The server system of claim 8 , wherein the executable code is further effective to cause the one or more processors to:
assign a unique host name to each unassigned IP address of the plurality of unassigned IP addresses; and
respond to hostname requests addressed to the each unassigned IP address of the plurality of unassigned IP addresses with the unique host name assigned to the each unassigned IP address.
11. The server system of claim 10 , wherein the executable code is further effective to cause the one or more processors to, for each unassigned IP address of the plurality of unassigned IP addresses:
transmit simulated traffic referencing the each unassigned IP address and the unique host name assigned to the each unassigned IP address.
12. The server system of claim 11 , wherein the simulated traffic is at least one of a host announcement and initiation of a registration process.
13. The server system of claim 11 , wherein the simulated traffic comprises a broadcast message according to at least one of:
NetBIOS (basic input output system) Name Service (NBNS) protocol using the unique host names;
Link-Local Multicast Name Resolution (LLMNR) protocol using the unique host names; and
multicast domain name resolution (mDNS) protocol using the unique host names.
14. The server system of claim 8 , wherein the executable code is further effective to cause the one or more processors to:
for each unassigned IP address of the plurality of unassigned IP addresses assign a grouping of services to the each unassigned IP address, the grouping of services being a subset of all services implemented by the server system;
receiving, by the server system, for a first IP address of the plurality of unassigned IP addresses, a first request for a first service;
if the first service is not included in the grouping of services assigned to the first IP address, transmit a response to the first request indicating that the first service is not available even though the first service is available on the server system; and
if the first service is included in the grouping of services assigned to the first IP address, respond to the first request using the first service.