Skip to content

M1037 Filter Network Traffic

Use network appliances to filter ingress or egress traffic and perform protocol-based filtering. Configure software on endpoints to filter network traffic.

Item Value
ID M1037
Version 1.1
Created 11 June 2019
Last Modified 20 June 2020
Navigation Layer View In ATT&CK® Navigator

Techniques Addressed by Mitigation

Domain ID Name Use
enterprise T1557 Adversary-in-the-Middle Use network appliances and host-based security software to block network traffic that is not necessary within the environment, such as legacy protocols that may be leveraged for AiTM conditions.
enterprise T1557.001 LLMNR/NBT-NS Poisoning and SMB Relay Use host-based security software to block LLMNR/NetBIOS traffic. Enabling SMB Signing can stop NTLMv2 relay attacks.8910
enterprise T1557.002 ARP Cache Poisoning Consider enabling DHCP Snooping and Dynamic ARP Inspection on switches to create mappings between IP addresses requested via DHCP and ARP tables and tie the values to a port on the switch that may block bogus traffic.56
enterprise T1557.003 DHCP Spoofing Consider filtering DHCP traffic on ports 67 and 68 to/from unknown or untrusted DHCP servers. Additionally, port security may also be enabled on layer switches. Furthermore, consider enabling DHCP snooping on layer 2 switches as it will prevent DHCP spoofing attacks and starvation attacks. Consider tracking available IP addresses through a script or a tool.
enterprise T1071 Application Layer Protocol -
enterprise T1071.004 DNS Consider filtering DNS requests to unknown, untrusted, or known bad domains and resources. Resolving DNS requests with on-premise/proxy servers may also disrupt adversary attempts to conceal data within DNS packets.
enterprise T1197 BITS Jobs Modify network and/or host firewall rules, as well as other network controls, to only allow legitimate BITS traffic.
enterprise T1530 Data from Cloud Storage Cloud service providers support IP-based restrictions when accessing cloud resources. Consider using IP allowlisting along with user account management to ensure that data access is restricted not only to valid users but only from expected IP ranges to mitigate the use of stolen credentials to access data.
enterprise T1602 Data from Configuration Repository Apply extended ACLs to block unauthorized protocols outside the trusted network.7
enterprise T1602.001 SNMP (MIB Dump) Apply extended ACLs to block unauthorized protocols outside the trusted network.7
enterprise T1602.002 Network Device Configuration Dump Apply extended ACLs to block unauthorized protocols outside the trusted network.7
enterprise T1499 Endpoint Denial of Service Leverage services provided by Content Delivery Networks (CDN) or providers specializing in DoS mitigations to filter traffic upstream from services.4 Filter boundary traffic by blocking source addresses sourcing the attack, blocking ports that are being targeted, or blocking protocols being used for transport. To defend against SYN floods, enable SYN Cookies.
enterprise T1499.001 OS Exhaustion Flood Leverage services provided by Content Delivery Networks (CDN) or providers specializing in DoS mitigations to filter traffic upstream from services.4 Filter boundary traffic by blocking source addresses sourcing the attack, blocking ports that are being targeted, or blocking protocols being used for transport. To defend against SYN floods, enable SYN Cookies.
enterprise T1499.002 Service Exhaustion Flood Leverage services provided by Content Delivery Networks (CDN) or providers specializing in DoS mitigations to filter traffic upstream from services.4 Filter boundary traffic by blocking source addresses sourcing the attack, blocking ports that are being targeted, or blocking protocols being used for transport.
enterprise T1499.003 Application Exhaustion Flood Leverage services provided by Content Delivery Networks (CDN) or providers specializing in DoS mitigations to filter traffic upstream from services.4 Filter boundary traffic by blocking source addresses sourcing the attack, blocking ports that are being targeted, or blocking protocols being used for transport.
enterprise T1499.004 Application or System Exploitation Leverage services provided by Content Delivery Networks (CDN) or providers specializing in DoS mitigations to filter traffic upstream from services.4 Filter boundary traffic by blocking source addresses sourcing the attack, blocking ports that are being targeted, or blocking protocols being used for transport.
enterprise T1048 Exfiltration Over Alternative Protocol Enforce proxies and use dedicated servers for services such as DNS and only allow those systems to communicate over respective ports/protocols, instead of all systems within a network. Cloud service providers support IP-based restrictions when accessing cloud resources. Consider using IP allowlisting along with user account management to ensure that data access is restricted not only to valid users but only from expected IP ranges to mitigate the use of stolen credentials to access data.
enterprise T1048.001 Exfiltration Over Symmetric Encrypted Non-C2 Protocol Enforce proxies and use dedicated servers for services such as DNS and only allow those systems to communicate over respective ports/protocols, instead of all systems within a network.
enterprise T1048.002 Exfiltration Over Asymmetric Encrypted Non-C2 Protocol Enforce proxies and use dedicated servers for services such as DNS and only allow those systems to communicate over respective ports/protocols, instead of all systems within a network.
enterprise T1048.003 Exfiltration Over Unencrypted Non-C2 Protocol Enforce proxies and use dedicated servers for services such as DNS and only allow those systems to communicate over respective ports/protocols, instead of all systems within a network.
enterprise T1187 Forced Authentication
Block SMB traffic from exiting an enterprise network with egress filtering or by blocking TCP ports 139, 445 and UDP port 137. Filter or block WebDAV protocol traffic from exiting the network. If access to external resources over SMB and WebDAV is necessary, then traffic should be tightly limited with allowlisting. 2 3
enterprise T1570 Lateral Tool Transfer Consider using the host firewall to restrict file sharing communications such as SMB. 1
enterprise T1599 Network Boundary Bridging Upon identifying a compromised network device being used to bridge a network boundary, block the malicious packets using an unaffected network device in path, such as a firewall or a router that has not been compromised. Continue to monitor for additional activity and to ensure that the blocks are indeed effective.
enterprise T1599.001 Network Address Translation Traversal Block Traffic Upon identifying a compromised network device being used to bridge a network boundary, block the malicious packets using an unaffected network device in path, such as a firewall or a router that has not been compromised. Continue to monitor for additional activity and to ensure that the blocks are indeed effective.
enterprise T1498 Network Denial of Service When flood volumes exceed the capacity of the network connection being targeted, it is typically necessary to intercept the incoming traffic upstream to filter out the attack traffic from the legitimate traffic. Such defenses can be provided by the hosting Internet Service Provider (ISP) or by a 3rd party such as a Content Delivery Network (CDN) or providers specializing in DoS mitigations.4
enterprise T1498.001 Direct Network Flood When flood volumes exceed the capacity of the network connection being targeted, it is typically necessary to intercept the incoming traffic upstream to filter out the attack traffic from the legitimate traffic. Such defenses can be provided by the hosting Internet Service Provider (ISP) or by a 3rd party such as a Content Delivery Network (CDN) or providers specializing in DoS mitigations.4
enterprise T1498.002 Reflection Amplification When flood volumes exceed the capacity of the network connection being targeted, it is typically necessary to intercept the incoming traffic upstream to filter out the attack traffic from the legitimate traffic. Such defenses can be provided by the hosting Internet Service Provider (ISP) or by a 3rd party such as a Content Delivery Network (CDN) or providers specializing in DoS mitigations.4
enterprise T1095 Non-Application Layer Protocol Filter network traffic to prevent use of protocols across the network boundary that are unnecessary.
enterprise T1572 Protocol Tunneling Consider filtering network traffic to untrusted or known bad domains and resources.
enterprise T1090 Proxy Traffic to known anonymity networks and C2 infrastructure can be blocked through the use of network allow and block lists. It should be noted that this kind of blocking may be circumvented by other techniques like Domain Fronting.
enterprise T1090.003 Multi-hop Proxy Traffic to known anonymity networks and C2 infrastructure can be blocked through the use of network allow and block lists. It should be noted that this kind of blocking may be circumvented by other techniques like Domain Fronting.
enterprise T1219 Remote Access Software Properly configure firewalls, application firewalls, and proxies to limit outgoing traffic to sites and services used by remote access tools.
enterprise T1021 Remote Services -
enterprise T1021.002 SMB/Windows Admin Shares Consider using the host firewall to restrict file sharing communications such as SMB. 1
enterprise T1021.005 VNC VNC defaults to TCP ports 5900 for the server, 5800 for browser access, and 5500 for a viewer in listening mode. Filtering or blocking these ports will inhibit VNC traffic utilizing default ports.
enterprise T1218 System Binary Proxy Execution -
enterprise T1218.012 Verclsid Consider modifying host firewall rules to prevent egress traffic from verclsid.exe.
enterprise T1205 Traffic Signaling Mitigation of some variants of this technique could be achieved through the use of stateful firewalls, depending upon how it is implemented.
enterprise T1205.001 Port Knocking Mitigation of some variants of this technique could be achieved through the use of stateful firewalls, depending upon how it is implemented.
enterprise T1205.002 Socket Filters Mitigation of some variants of this technique could be achieved through the use of stateful firewalls, depending upon how it is implemented.
enterprise T1537 Transfer Data to Cloud Account Implement network-based filtering restrictions to prohibit data transfers to untrusted VPCs.
enterprise T1552 Unsecured Credentials Limit access to the Instance Metadata API. A properly configured Web Application Firewall (WAF) may help prevent external adversaries from exploiting Server-side Request Forgery (SSRF) attacks that allow access to the Cloud Instance Metadata API.11
enterprise T1552.005 Cloud Instance Metadata API Limit access to the Instance Metadata API. A properly configured Web Application Firewall (WAF) may help prevent external adversaries from exploiting Server-side Request Forgery (SSRF) attacks that allow access to the Cloud Instance Metadata API.11

References

  1. Microsoft. (2020, March 10). Preventing SMB traffic from lateral connections and entering or leaving the network. Retrieved June 1, 2020. ↩↩

  2. US-CERT. (2017, March 16). SMB Security Best Practices. Retrieved December 21, 2017. ↩

  3. US-CERT. (2017, October 20). Alert (TA17-293A): Advanced Persistent Threat Activity Targeting Energy and Other Critical Infrastructure Sectors. Retrieved November 2, 2017. ↩

  4. Meintanis, S., Revuelto, V., Socha, K.. (2017, March 10). DDoS Overview and Response Guide. Retrieved April 24, 2019. ↩↩↩↩↩↩↩↩

  5. King, J., Lauerman, K. (2016, January 22). ARP Poisoning (Man-in-the-Middle) Attack and Mitigation Technique. Retrieved October 15, 2020. ↩

  6. Juniper. (2020, September 23). Understanding and Using Dynamic ARP Inspection (DAI). Retrieved October 15, 2020. ↩

  7. US-CERT. (2017, June 5). Reducing the Risk of SNMP Abuse. Retrieved October 19, 2020. ↩↩↩

  8. Salvati, M. (2017, June 2). Practical guide to NTLM Relaying in 2017 (A.K.A getting a foothold in under 5 minutes). Retrieved February 7, 2019. ↩

  9. Kuehn, E. (2018, April 11). Ever Run a Relay? Why SMB Relays Should Be On Your Mind. Retrieved February 7, 2019. ↩

  10. Microsoft. (2008, September 10). Using SMB Packet Signing. Retrieved February 7, 2019. ↩

  11. Higashi, Michael. (2018, May 15). Instance Metadata API: A Modern Day Trojan Horse. Retrieved July 16, 2019. ↩↩

  12. Mollema, D. (2019, March 4). The worst of both worlds: Combining NTLM Relaying and Kerberos delegation . Retrieved August 15, 2022. ↩