Techniques
Sample rules
Firewall Rule Deleted Via Netsh.EXE
- source: sigma
- technicques:
- t1562
- t1562.004
Description
Detects the removal of a port or application rule in the Windows Firewall configuration using netsh
Detection logic
condition: all of selection_* and not 1 of filter_optional_*
filter_optional_dropbox:
CommandLine|contains: name=Dropbox
ParentImage|endswith: \Dropbox.exe
selection_cli:
CommandLine|contains|all:
- firewall
- 'delete '
selection_img:
- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe
RDP Connection Allowed Via Netsh.EXE
- source: sigma
- technicques:
- t1562
- t1562.004
Description
Detects usage of the netsh command to open and allow connections to port 3389 (RDP). As seen used by Sarwent Malware
Detection logic
condition: all of selection_*
selection_cli:
CommandLine|contains:
- portopening
- allow
CommandLine|contains|all:
- 'firewall '
- 'add '
- 'tcp '
- '3389'
selection_img:
- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe
New Network Trace Capture Started Via Netsh.EXE
- source: sigma
- technicques:
- t1040
Description
Detects the execution of netsh with the “trace” flag in order to start a network capture
Detection logic
condition: all of selection_*
selection_cli:
CommandLine|contains|all:
- trace
- start
selection_img:
- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe
Firewall Disabled via Netsh.EXE
- source: sigma
- technicques:
- t1562
- t1562.004
Description
Detects netsh commands that turns off the Windows firewall
Detection logic
condition: selection_img and 1 of selection_cli_*
selection_cli_1:
CommandLine|contains|all:
- firewall
- set
- opmode
- disable
selection_cli_2:
CommandLine|contains|all:
- advfirewall
- set
- state
- 'off'
selection_img:
- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe
Nltest.EXE Execution
- source: sigma
- technicques:
- t1016
- t1018
- t1482
Description
Detects nltest commands that can be used for information discovery
Detection logic
condition: selection
selection:
- Image|endswith: \nltest.exe
- OriginalFileName: nltestrk.exe
Netsh Allow Group Policy on Microsoft Defender Firewall
- source: sigma
- technicques:
- t1562
- t1562.004
Description
Adversaries may modify system firewalls in order to bypass controls limiting network usage
Detection logic
condition: all of selection_*
selection_cli:
CommandLine|contains|all:
- advfirewall
- firewall
- set
- rule
- group=
- new
- enable=Yes
selection_img:
- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe
New Port Forwarding Rule Added Via Netsh.EXE
- source: sigma
- technicques:
- t1090
Description
Detects the execution of netsh commands that configure a new port forwarding (PortProxy) rule
Detection logic
condition: selection_img and 1 of selection_cli_*
selection_cli_1:
CommandLine|contains|all:
- interface
- portproxy
- add
- v4tov4
selection_cli_2:
CommandLine|contains|all:
- 'i '
- 'p '
- 'a '
- 'v '
selection_cli_3:
CommandLine|contains|all:
- connectp
- listena
- c=
selection_img:
- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe
New Firewall Rule Added Via Netsh.EXE
- source: sigma
- technicques:
- t1562
- t1562.004
Description
Detects the addition of a new rule to the Windows firewall via netsh
Detection logic
condition: all of selection_* and not 1 of filter_optional_*
filter_optional_dropbox:
CommandLine|contains:
- advfirewall firewall add rule name=Dropbox dir=in action=allow "program=?:\Program
Files (x86)\Dropbox\Client\Dropbox.exe" enable=yes profile=Any
- advfirewall firewall add rule name=Dropbox dir=in action=allow "program=?:\Program
Files\Dropbox\Client\Dropbox.exe" enable=yes profile=Any
selection_cli:
CommandLine|contains|all:
- ' firewall '
- ' add '
selection_img:
- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe
Firewall Rule Update Via Netsh.EXE
- source: sigma
- technicques:
Description
Detects execution of netsh with the “advfirewall” and the “set” option in order to set new values for properties of a existing rule
Detection logic
condition: all of selection_*
selection_cli:
CommandLine|contains|all:
- ' firewall '
- ' set '
selection_img:
- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe
RDP Port Forwarding Rule Added Via Netsh.EXE
- source: sigma
- technicques:
- t1090
Description
Detects the execution of netsh to configure a port forwarding of port 3389 (RDP) rule
Detection logic
condition: all of selection_*
selection_cli:
CommandLine|contains|all:
- ' i'
- ' p'
- =3389
- ' c'
selection_img:
- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe