Impair Defenses: Disable or Modify System Firewall

APT29 used netsh to configure firewall rules that limited certain UDP outbound packets.^[1]

APT38 have created firewall exemptions on specific ports, including ports 443, 6443, 8443, and 9443.^[2]

The "ZR" variant of BACKSPACE will check to see if known host-based firewalls are installed on the infected systems. BACKSPACE will attempt to establish a C2 channel, then will examine open windows to identify a pop-up from the firewall software and will simulate a mouse-click to allow the connection to proceed.^[3]

BADCALL disables the Windows firewall before binding to a port.^[4]

Carbanak may use netsh to add local firewall rule exceptions.^[5]

CookieMiner has checked for the presence of "Little Snitch", macOS network monitoring and application firewall software, stopping and exiting if it is found.^[6]

Cyclops Blink can modify the Linux iptables firewall to enable C2 communication via a stored list of port numbers.^[7][8]

DarkComet can disable Security Center functions like the Windows Firewall.^[9][10]

Dragonfly has disabled host-based firewalls. The group has also globally opened port 3389.^[11]

Grandoreiro can block the Deibold Warsaw GAS Tecnologia security tool at the firewall level.^[12]

H1N1 kills and disables services for Windows Firewall.^[13]

HARDRAIN opens the Windows Firewall to modify incoming connections.^[14]

HOPLIGHT has modified the firewall using netsh.^[15]

InvisiMole has a command to disable routing and the Firewall on the victim’s machine.^[16]

Kasidet has the ability to change firewall settings to allow a plug-in to be downloaded.^[17]

Kimsuky has been observed disabling the system firewall.^[18]

Various Lazarus Group malware modifies the Windows firewall to allow incoming connections or disable it entirely using netsh. ^[19][20][21]

NanoCore can modify the victim's firewall.^[22][23]

netsh can be used to disable local firewall settings.^[24][25]

njRAT has modified the Windows firewall to allow itself to communicate through the firewall.^[26][27]

Operation Wocao has used PowerShell to add and delete rules in the Windows firewall.^[28]

Remsec can add or remove applications or ports on the Windows firewall or disable it entirely.^[29]

Rocke used scripts which killed processes and added firewall rules to block traffic related to other cryptominers.^[30]

TeamTNT has disabled iptables.^[31]

TYPEFRAME can open the Windows Firewall on the victim’s machine to allow incoming connections.^[32]

ZxShell can disable the firewall by modifying the registry key HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile.^[33]

Ensure proper process and file permissions are in place to prevent adversaries from disabling or modifying firewall settings.

Ensure proper Registry permissions are in place to prevent adversaries from disabling or modifying firewall settings.

Ensure proper user permissions are in place to prevent adversaries from disabling or modifying firewall settings.