diff --git a/detections/endpoint/windows_remote_access_software_brc4_loaded_dll.yml b/detections/endpoint/windows_remote_access_software_brc4_loaded_dll.yml deleted file mode 100644 index 6801bc82b1..0000000000 --- a/detections/endpoint/windows_remote_access_software_brc4_loaded_dll.yml +++ /dev/null @@ -1,79 +0,0 @@ -name: Windows Remote Access Software BRC4 Loaded Dll -id: 73cf5dcb-cf36-4167-8bbe-384fe5384d05 -version: 1 -date: '2022-08-24' -author: Teoderick Contreras, Splunk -type: Anomaly -datamodel: -- Endpoint -description: The following anomaly detection identifies the behavior related to 4 native Windows DLLs being loaded by a non-standard process. - Identified by MDSec during their research into Brute Ratel, MDSec identified a high signal analytic by calling out these 4 DLLs being loaded - into a process. LogonCLI.dll is the Net Logon Client DLL and is related to users and other domain services to get authenticated. Credui.dll - is Credential Manager User Interface. Credential managers receive notifications when authentication information changes. - For example, credential managers are notified when a user logs on or an account password changes. - Samcli.dll is the Security Accounts Manager Client DLL. Adversaries may attempt to extract credential material from the Security Account Manager (SAM) - database either through in-memory techniques or through the Windows Registry where the SAM database is stored. - Dbghelp.dll is Windows Image Helper. Windows Image Helper is commonly seen in credential dumping due to native functions. - All of these modules are important to monitor and track and combined may lead to credentail access or dumping. -search: '`sysmon` EventCode=7 - |bin _time span=30s - | eval BRC4_AnomalyLoadedDll=case(OriginalFileName=="credui.dll", 1, OriginalFileName=="DBGHELP.DLL", 1, OriginalFileName=="SAMCLI.DLL", 1, OriginalFileName=="winhttp.dll", 1, 1=1, 0) - | eval BRC4_LoadedDllPath=case(match(ImageLoaded, "credui.dll"), 1, match(ImageLoaded, "dbghelp.dll"), 1, match(ImageLoaded, "samcli.dll"), 1, match(ImageLoaded, "winhttp.dll"), 1, 1=1, 0) - | stats count min(_time) as firstTime max(_time) as lastTime values(ImageLoaded) as ImageLoaded values(OriginalFileName) as OriginalFileName dc(ImageLoaded) as ImageLoadedCount by Image BRC4_LoadedDllPath BRC4_AnomalyLoadedDll Computer EventCode Signed - | where ImageLoadedCount == 4 AND (BRC4_LoadedDllPath == 1 OR BRC4_AnomalyLoadedDll == 1) - | `security_content_ctime(firstTime)` - | `security_content_ctime(lastTime)` - | `windows_remote_access_software_brc4_loaded_dll_filter`' -how_to_implement: The latest Sysmon TA 3.0 https://splunkbase.splunk.com/app/5709 will - add the ImageLoaded name to the process_name field, allowing this query to work. Use as an example and implement for other products. -known_false_positives: This module can be loaded by a third party application. Filter is needed. -references: -- https://unit42.paloaltonetworks.com/brute-ratel-c4-tool/ -- https://www.mdsec.co.uk/2022/08/part-3-how-i-met-your-beacon-brute-ratel/ -- https://strontic.github.io/xcyclopedia/library/logoncli.dll-138871DBE68D0696D3D7FA91BC2873B1.html -- https://strontic.github.io/xcyclopedia/library/credui.dll-A5BD797BBC2DD55231B9DE99837E5461.html -- https://docs.microsoft.com/en-us/windows/win32/secauthn/credential-manager -- https://strontic.github.io/xcyclopedia/library/samcli.dll-522D6D616EF142CDE965BD3A450A9E4C.html -- https://strontic.github.io/xcyclopedia/library/dbghelp.dll-15A55EAB307EF8C190FE6135C0A86F7C.html -tags: - analytic_story: - - Brute Ratel C4 - asset_type: Endpoint - cis20: - - CIS 3 - - CIS 5 - - CIS 16 - confidence: 30 - context: - - Source:Endpoint - dataset: - - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/brute_ratel/iso_version_dll_campaign/sysmon.log - impact: 30 - kill_chain_phases: - - Exploitation - message: a process $Image$ loaded several modules $ImageLoaded$ that might related to credential access on $Computer$. - mitre_attack_id: - - T1219 - - T1003 - nist: - - DE.CM - observable: - - name: Computer - type: Endpoint - role: - - Victim - product: - - Splunk Enterprise - - Splunk Enterprise Security - - Splunk Cloud - required_fields: - - _time - - Image - - ImageLoaded - - process_name - - Computer - - EventCode - - Signed - - ProcessId - risk_score: 9 - security_domain: endpoint