OS Credential Dumping: DCSync T1003.006

Tactic: Credential Access

Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API) to simulate the replication process from a remote domain controller using a technique called DCSync.

Events covered

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

Authoring guide

Patterns shared across the 26 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names 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 (37 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
Properties8contains 6, in 21131f6aa-9c07-11d1-f79f-00c04fc2dcd2, 1131f6ad-9c07-11d1-f79f-00c04fc2dcd2, 89e95b76-444d-4c62-991a-0facbeda640c, *Manage Replication Topology*, *Remove Replica In Domain*
EventID7eq 74662, 1, 10, 4624, 4656
AccessMask6eq 60x100, 256
SubjectUserName5ends_with 4, starts_with 2, eq 1$, MSOL_, *$, NT AUT
Codename3eq 3DCSync
MessageType3eq 32
ScriptBlockText3contains 1, eq 1, in 1-all , -server , add-constraineddelegationbackdoor, add-domaingroupmember, add-domainobjectacl
Channel2eq 2, in 2
CommandLine2contains 1, match 1(?i)KERNELBASE.dll, (?i)mimikatz, (?i)ntdll.dll, ::aadcookie, ::detours
LogonType2eq 2Network
ObjectType2in 2%{19195a5b-6da0-11d0-afd3-00c04fd930c9}, domainDNS
SubjectDomainName2eq 2Window Manager
SubjectUserSid2eq 2, starts_with 1S-1-5-18, S-1-5-7, nt aut
event.category2eq 2process
eventtype2eq 2

Top indicator values (471 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. Click a value to expand the rules under this technique that use it.

FieldKindValueRules (here)Corpus reach
Propertiescontains
1131f6aa-9c07-11d1-f79f-00c04fc2dcd2
66
Propertiescontains
1131f6ad-9c07-11d1-f79f-00c04fc2dcd2
66
Propertiescontains
89e95b76-444d-4c62-991a-0facbeda640c
66
Propertiescontains
ds-replication-get-changes
22
Propertiescontains
ds-replication-get-changes-all
22
Propertiescontains
ds-replication-get-changes-in-filtered-set
22
AccessMaskeq
0x100
55
AccessMaskeq
256
1
EventIDeq
4662
513
SubjectUserNameends_with
$
43
Codenameeq
DCSync
33
MessageTypeeq
2
321
LogonTypeeq
Network
240
ObjectTypein
%{19195a5b-6da0-11d0-afd3-00c04fd930c9}
22
ObjectTypein
domainDNS
22
Propertiesin
*Manage Replication Topology*
22
Propertiesin
*Remove Replica In Domain*
22
Propertiesin
*Replicating Directory Changes All*
22
Propertiesin
*{1131f6ac-9c07-11d1-f79f-00c04fc2dcd2}*
22
Propertiesin
*{1131f6ad-9c07-11d1-f79f-00c04fc2dcd2}*
22
Propertiesin
*{9923a32a-3607-11d2-b9be-0000f87a36b2}*
22
SubjectDomainNameeq
Window Manager
2
SubjectUserNamestarts_with
MSOL_
2
event.categoryeq
process
2128
AccountTypene
Machine
12
All_Traffic.appin
*drsr*
1
All_Traffic.appin
ad drs
1
All_Traffic.appin
ms-dc-replication
1
AttributeLDAPDisplayNameeq
ntsecuritydescriptor
17
AttributeValuecontains
1131f6aa-9c07-11d1-f79f-00c04fc2dcd2;;s-1-5-21-
1

Exclusions (16 distinct)

Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. 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. Click a value to expand the rules under this technique that exclude it.

FieldKindValueRules excluding
SubjectUserNameends_with
$
6
SubjectUserNamestarts_with
MSOL_
4
SubjectUserNamestarts_with
NT AUT
1
SubjectDomainNameeq
Window Manager
2
ScriptBlockTexteq
sentinelbreakpoints
1
ScriptBlockTexteq
set-psbreakpoint
1
SubjectUserNameeq
*$
1
SubjectUserSideq
S-1-5-18
1
SubjectUserSideq
S-1-5-7
1
SubjectUserSidstarts_with
nt aut
1
src_categoryeq
domain_controller
1
src_ipeq
%domain_controllers%
1
src_ipeq
%exchange_servers%
1
userregex_match
.*\$
1
user.idin
S-1-5-18
1

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.

Platform (all)
Domain (all)

Sigma 10 rules

Elastic 5 rules

Splunk 7 rules

Kusto 4 rules