HackTool - RemoteKrbRelay Execution

Severity: high
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects the use of RemoteKrbRelay, a Kerberos relaying tool via CommandLine flags and PE metadata.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1558.003` Steal or Forge Kerberos Tickets: Kerberoasting

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `selection_img`

or:
Image|endswith: '\RemoteKrbRelay.exe'
OriginalFileName: RemoteKrbRelay.exe

Stage 2: `selection_cli_required`

CommandLine|contains: ' -clsid '
CommandLine|contains: ' -target '
CommandLine|contains: ' -victim '

Stage 3: `all of selection_cli_attack_rbcd_main`

CommandLine|contains: '-rbcd '

Stage 4: `all of selection_cli_attack_rbcd_options`

or:
CommandLine|contains: '--computername '
CommandLine|contains: '-cn '

Stage 5: `selection_cli_attack_changepass`

CommandLine|contains: '-chp '
CommandLine|contains: '-chpPass '
CommandLine|contains: '-chpUser '

Stage 6: `selection_cli_attack_addgrpname`

CommandLine|contains: '-addgroupmember '
CommandLine|contains: '-group '
CommandLine|contains: '-groupuser '

Stage 7: `selection_cli_attack_smb`

or:
CommandLine|contains: interactive
CommandLine|contains: secrets
CommandLine|contains: service-add
CommandLine|contains: '--smbkeyword '
CommandLine|contains: '-smb '

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`CommandLine`	match	`-clsid` corpus 2 (sigma 2) `-target` `-victim` `--computername` `--smbkeyword` `-addgroupmember` `-chp` `-chpPass` `-chpUser` `-cn` `-group` `-groupuser` `-rbcd` `-smb` `interactive` corpus 2 (sigma 2) `secrets` `service-add`
`Image`	ends_with	`\RemoteKrbRelay.exe`
`OriginalFileName`	eq	`RemoteKrbRelay.exe`

HackTool - RemoteKrbRelay Execution

MITRE ATT&CK coverage

Event coverage

Stages and Predicates

Stage 1: selection_img

Stage 2: selection_cli_required

Stage 3: all of selection_cli_attack_rbcd_main

Stage 4: all of selection_cli_attack_rbcd_options

Stage 5: selection_cli_attack_changepass

Stage 6: selection_cli_attack_addgrpname

Stage 7: selection_cli_attack_smb