ATT&CK coverage › Technique

Remote Services T1021

Adversaries may use Valid Accounts to log into a service that accepts remote connections, such as telnet, SSH, and VNC. The adversary may then perform actions as the logged-on user.

Events covered

8 catalog events are tagged with this technique by at least one rule.

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon13RegistryEvent (Value Set)
Security-Auditing4624An account was successfully logged on.
Security-Auditing4672Special privileges assigned to new logon.
Security-Auditing4688A new process has been created.
Security-Auditing4697A service was installed in the system.
Security-Auditing4698A scheduled task was created.
Security-Auditing5145A network share object was checked to see whether client can be granted desired access.

Authoring guide

Patterns shared across the 11 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (17 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
EventType3eq 3scheduled-task-created, logged-in, service-installed, logged-in-special
Image3ends_with 3\nxc.exe, \powershell.exe, \cmd.exe, \psexec.exe
CommandLine3match 3 mssql , rdp , nfs , -pw , -ssh
source.ip2ne 2127.0.0.1, ::1, ::
OriginalFileName2eq 2PowerShell.EXE, Cmd.Exe, psexec.c
user1ends_with 1$
computer_name1starts_with 1
RpcCallClientLocality1eq 10
ClientProcessId1eq 10
event.outcome1eq 1success
LogonType1eq 1Network
RelativeTargetName1eq 1winreg
PrivilegeList1eq 1SeBackupPrivilege
Ratio1gt 1threshold
registry_path1eq 1"*\\CurrentControlSet\\Control\\Terminal...

Top indicator values (43 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique.

FieldKindValueRules (here)Corpus reach
source.ipne::127
source.ipne127.0.0.128
userends_with$118
source.ipne::1
ClientProcessIdeq012
RpcCallClientLocalityeq01
EventTypeeqscheduled-task-created13
EventTypeeqlogged-in17
LogonTypeeqNetwork14
event.outcomeeqsuccess18
EventTypeeqservice-installed12
RelativeTargetNameeqwinreg1
PrivilegeListeqSeBackupPrivilege1
EventTypeeqlogged-in-special1
Ratiogtthreshold1
CommandLinematch wmi 1
CommandLinematch vnc 1
CommandLinematch winrm 1
CommandLinematch ftp 1
CommandLinematch nfs 1

Common exclusions (26 distinct)

Field/operator/value combinations that rules under this technique routinely exclude (top-level not() clauses). These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths.

FieldKindValueRules excluding
ServiceFileNamewildcard?:\Windows\System32\wbem\WmiApSrv.exe1
ServiceFileNamewildcard?:\Pella Corporation\Pella Order Management\GPAutoSvc.exe1
ServiceFileNamewildcard?:\Windows\System32\upfc.exe1
ServiceFileNamewildcard?:\Windows\AdminArsenal\PDQ*.exe1
ServiceFileNamewildcard?:\WINDOWS\RemoteAuditService.exe1
ServiceFileNamewildcard?:\Program Files (x86)\*.exe1
ServiceFileNamewildcard?:\Windows\System32\sppsvc.exe1
ServiceFileNamewildcard?:\Windows\System32\vds.exe1
ServiceFileNamewildcard?:\Windows\System32\VSSVC.exe1
ServiceFileNamewildcard?:\Windows\VeeamVssSupport\VeeamGuestHelper.exe1
ServiceFileNamewildcard?:\Windows\System32\taskhostex.exe1
ServiceFileNamewildcard?:\Windows\System32\svchost.exe1
ServiceFileNamewildcard?:\Windows\servicing\TrustedInstaller.exe1
ServiceFileNamewildcard?:\Windows\ADCR_Agent\adcrsvc.exe1
ServiceFileNamewildcard?:\Windows\ProPatches\Scheduler\STSchedEx.exe1

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Sigma 4 rules

Elastic 4 rules

Splunk 1 rule

Kusto Query Language 2 rules