diff --git a/rules/linux/builtin/lnx_privileged_user_creation.yml b/rules/linux/builtin/lnx_privileged_user_creation.yml new file mode 100644 index 000000000..ceb66f538 --- /dev/null +++ b/rules/linux/builtin/lnx_privileged_user_creation.yml @@ -0,0 +1,34 @@ +title: Privileged User Has Been Created +id: 0ac15ec3-d24f-4246-aa2a-3077bb1cf90e +status: experimental +description: Detects the addition of a new user to a privileged group such as "root" or "sudo" +references: + - https://digital.nhs.uk/cyber-alerts/2018/cc-2825 + - https://linux.die.net/man/8/useradd + - https://github.com/redcanaryco/atomic-red-team/blob/25acadc0b43a07125a8a5b599b28bbc1a91ffb06/atomics/T1136.001/T1136.001.md#atomic-test-5---create-a-new-user-in-linux-with-root-uid-and-gid +author: Pawel Mazur +date: 2022/12/21 +tags: + - attack.persistence + - attack.t1136.001 + - attack.t1098 +logsource: + product: linux + definition: '/var/log/secure on REHL systems or /var/log/auth.log on debian like Systems needs to be collected in order for this detection to work' +detection: + # Example of the events that could be observed when matching these would be as follow + # Dec 21 16:42:19 testserver useradd[1337]: new user: name=butter1, UID=1000, GID=0, home=/root, shell=/bin/bash + # Dec 21 17:13:54 testserver useradd[1337]: new user: name=john, UID=0, GID=0, home=/home/john, shell=/bin/bash + # Dec 21 17:24:40 testserver useradd[1337]: new user: name=butter3, UID=1000, GID=10, home=/home/butter3, shell=/bin/bash + # Dec 21 17:30:22 testserver useradd[1337]: new user: name=butter4, UID=1000, GID=27, home=/home/butter4, shell=/bin/bash + selection_new_user: + - 'new user' + selection_uids_gids: + - 'GID=0' # root group + - 'UID=0' # root UID + - 'GID=10' # wheel group + - 'GID=27' # sudo group + condition: all of selection_* +falsepositives: + - Administrative activity +level: high diff --git a/rules/linux/process_creation/proc_creation_lnx_usermod_susp_group.yml b/rules/linux/process_creation/proc_creation_lnx_usermod_susp_group.yml new file mode 100644 index 000000000..fe2386dde --- /dev/null +++ b/rules/linux/process_creation/proc_creation_lnx_usermod_susp_group.yml @@ -0,0 +1,25 @@ +title: User Added To Root/Sudoers Group Using Usermod +id: 6a50f16c-3b7b-42d1-b081-0fdd3ba70a73 +status: experimental +description: Detects usage of the "usermod" binary to add users add users to the root or suoders groups +references: + - https://pberba.github.io/security/2021/11/23/linux-threat-hunting-for-persistence-account-creation-manipulation/ + - https://www.configserverfirewall.com/ubuntu-linux/ubuntu-add-user-to-root-group/ +author: TuanLe (GTSC) +date: 2022/12/21 +tags: + - attack.privilege_escalation + - attack.persistence +logsource: + product: linux + category: process_creation +detection: + selection: + Image|endswith: '/usermod' + CommandLine|contains: + - '-aG root' + - '-aG sudoers' + condition: selection +falsepositives: + - Legitimate administrator activities +level: medium diff --git a/rules/windows/process_creation/proc_creation_win_impersonate_tool.yml b/rules/windows/process_creation/proc_creation_win_impersonate_tool.yml new file mode 100644 index 000000000..417f3166e --- /dev/null +++ b/rules/windows/process_creation/proc_creation_win_impersonate_tool.yml @@ -0,0 +1,38 @@ +title: Impersonate Execution +id: cf0c254b-22f1-4b2b-8221-e137b3c0af94 +status: experimental +description: Detects execution of the Impersonate tool. Which can be used to manipulate tokens on a Windows computers remotely (PsExec/WmiExec) or interactively +references: + - https://sensepost.com/blog/2022/abusing-windows-tokens-to-compromise-active-directory-without-touching-lsass/ + - https://github.com/sensepost/impersonate +author: Sai Prashanth Pulisetti @pulisettis +date: 2022/12/21 +tags: + - attack.privilege_escalation + - attack.defense_evasion + - attack.t1134.001 + - attack.t1134.003 +logsource: + product: windows + category: process_creation +detection: + selection_commandline_exe: + CommandLine|contains: 'impersonate.exe' + selection_commandline_opt: + CommandLine|contains: + - ' list ' + - ' exec ' + - ' adduser ' + selection_hash_plain: + Hashes|contains: + - 'MD5=9520714AB576B0ED01D1513691377D01' + - 'SHA256=E81CC96E2118DC4FBFE5BAD1604E0AC7681960143E2101E1A024D52264BB0A8A' + - 'IMPHASH=0A358FFC1697B7A07D0E817AC740DF62' + selection_hash_ext: + - MD5: '9520714AB576B0ED01D1513691377D01' + - SHA256: 'E81CC96E2118DC4FBFE5BAD1604E0AC7681960143E2101E1A024D52264BB0A8A' + - IMPHASH: '0A358FFC1697B7A07D0E817AC740DF62' + condition: all of selection_commandline_* or 1 of selection_hash_* +falsepositives: + - Unknown +level: medium