Adversary-in-the-Middle T1557

Tactics: Credential Access, Collection

Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as Network Sniffing, Transmitted Data Manipulation, or replay attacks (Exploitation for Credential Access). By abusing features of common networking protocols that can determine the flow of network traffic (e.g. ARP, DNS, LLMNR, etc.), adversaries may force a device to communicate through an adversary controlled system so they can collect information or perform additional actions.

Events covered

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

Authoring guide

Patterns shared across the 61 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 (90 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
CommandLine7contains 7, ends_with 1, match 1 --adcs , --port , /ntlm:ntlmhash , ntlmrelay, smbrelay
src_ip7is_not_null 4, ne 4, eq 2, cidr_match 1::1, 127.0.0.1, %exchange_server_ips%, 127.0.0.0/8, ::
EventType6eq 5, in 1AssociateVPCWithHostedZone, DEVICE_REGISTER_UNREGISTER_EVENT, authorize, exec, logged-in
Image6ends_with 5, contains 2\gup.exe, \atexec_windows.exe, \cmd.exe, \cscript.exe, \dcomexec_windows.exe
LogonType6eq 6Network
AuthenticationPackageName5eq 5NTLM, Kerberos
EventID5eq 55137, 4662, 5136, 4624, 4688
ObjectDN5contains 2, starts_with 2, wildcard 1*UWhRC*BAAAA*MicrosoftDNS*, 1uwhrca, DC=*,, DC=wpad,, aaaaa
ObjectClass4eq 4dnsNode
Provider_Name4eq 4Microsoft-Windows-DistributedCOM, Microsoft-Windows-Iphlpsvc, login, route53.amazonaws.com
event.type4eq 3, in 1change, start, process_started
facility4eq 4PM, DHCP_SNOOPING, PORT_SECURITY, SISF
mnemonic4eq 3, in 1ERR_DISABLE, DHCP_SNOOPING_UNTRUSTED_PORT, IP_THEFT, MAC_AND_IP_THEFT, MAC_THEFT
user4ends_with 4, ne 1$
AdditionalInfo3contains 2, wildcard 1*UWhRC*BAAAA*MicrosoftDNS*, 1uwhrca, aaaaa, baaaa, cn=microsoftdns

Top indicator values (398 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
LogonTypeeq
Network
640
ObjectClasseq
dnsNode
44
src_ipne
127.0.0.1
423
src_ipne
::1
421
userends_with
$
45
AuthenticationPackageNameeq
NTLM
39
AuthenticationPackageNameeq
Kerberos
25
EventIDeq
5137
36
EventIDeq
4662
213
EventIDeq
5136
230
AppDisplayNameeq
Azure Portal
22
Imagecontains
\ntlmrelayx
23
Imagecontains
\smbrelayx
23
Imageends_with
\gup.exe
25
computer_namestarts_with
substring(user.name, 0, -1)
22
event.outcomeeq
success
2251
event.typeeq
change
277
facilityeq
PM
22
file.nameeq
FssagentRpc
23
file.nameeq
Spoolss
23
file.nameeq
WinsPipe
22
file.nameeq
dhcpserver
22
file.nameeq
dnsserver
22
file.nameeq
efsrpc
23
file.nameeq
eventlog
22
file.nameeq
lsarpc
23
file.nameeq
lsass
23
file.nameeq
netdfs
23
file.nameeq
netlogon
23
file.nameeq
samr
23

Exclusions (66 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
src_ipends_with
host.ip
4
computer_namestarts_with
substring(user.name, 0, -1)
2
EventDatacontains
gc_service.exe
1
EventDatacontains
gc_worker.exe
1
Imagecontains
hotpotatoes
1
Imagecontains
hotpotatoes6
1
Imagecontains
hotpotatoes7
1
Imagewildcard
?:\program files (x86)\*.exe
1
Imagewildcard
?:\program files\*.exe
1
Imagewildcard
?:\programdata\bomgar-*\*\bomgar-scc.exe
1
Imagewildcard
?:\programdata\bomgar-*\*\sra-pin.exe
1
Imagewildcard
?:\programdata\ctes\components\sng\abtsngsvc.exe
1
Imagewildcard
?:\programdata\ctes\components\svc\cteshostsvc.exe
1
Imagewildcard
?:\programdata\ctes\ctes.exe
1
Imagewildcard
?:\programdata\lenovo\vantage\addins\lenovohardwarescanaddin\*\ldeapi.server.exe
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 23 rules

Elastic 19 rules

Splunk 11 rules

Kusto 8 rules