Hide Artifacts: Hidden Users T1564.002

Tactic: Stealth

Adversaries may use hidden users to hide the presence of user accounts they create or modify. Administrators may want to hide users when there are many user accounts on a given system or if they want to hide their administrative or other management accounts from other users.

Events covered

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

Authoring guide

Patterns shared across the 10 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 (18 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
CommandLine5contains 3, match 2, regex_match 2(?i)(\s+ADD\s+.*\/d.*0), (?i)(REG\s+?ADD).*\x5cCurrentVersion\x5cWinlogon\x5cSpeci..., ([0-9]|[1-9][0-9]|[1-4][0-9]{2}), /cfg, /configure
Image3ends_with 3/dscl, \reg.exe, \secedit.exe
event.type3in 2, eq 1start, change, creation, process_started
host.os.type3eq 3
EventID2eq 21, 12, 13, 4657, 4688
EventType2eq 1, in 1exec, ssh_login, user_login
TargetObject2contains 1, wildcard 1\registry\machine\sam\sam\domains\account\users\names\*$\, \software\microsoft\windows..., hklm\sam\sam\domains\account\users\names\*$\, machine\sam\sam\domains\account\users\names\*$\
event.category2eq 2authentication, process
signature_id2contains 212, 13, 4657
user2in 2backup, _apt, _chrony, avahi, bin
Details1eq 1DWORD (0x00000000)
OriginalFileName1eq 1secedit
ParentImage1is_not_null 1
Type1eq 1
event.outcome1eq 1success

Top indicator values (97 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
CommandLinematch
(?i)(\s+ADD\s+.*\/d.*0)
22
userin
backup
22
userin
bin
22
userin
dnsmasq
22
userin
games
22
userin
gnats
22
userin
irc
22
userin
list
22
userin
mail
22
userin
man
22
userin
messagebus
22
userin
news
22
userin
proxy
22
userin
sshd
22
userin
sys
22
userin
systemd-timesync
22
userin
uucp
22
CommandLinecontains
/cfg
12
CommandLinecontains
/configure
12
CommandLinecontains
/d 0
12
CommandLinecontains
/db
12
CommandLinecontains
/export
12
CommandLinecontains
/v
15
CommandLinecontains
1
1
CommandLinecontains
\software\microsoft\windows nt\currentversion\winlogon\specialaccounts\userlist
1
CommandLinecontains
add
134
CommandLinecontains
create
124
CommandLinecontains
ishidden
1
CommandLinecontains
true
13
CommandLinecontains
uniqueid
1

Exclusions (53 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
Imagein
/opt/gitlab/embedded/bin/bundle
1
Imagein
/run/podman-init
1
Imagein
/usr/bin/atq
1
Imagein
/usr/bin/atrm
1
Imagein
/usr/bin/basename
1
Imagein
/usr/bin/date
1
Imagein
/usr/bin/dircolors
1
Imagein
/usr/bin/env
1
Imagein
/usr/bin/locale
1
Imagein
/usr/bin/readlink
1
Imagein
/usr/bin/tr
1
Imagein
/usr/sbin/sendmail
1
ParentCommandLineeq
runc init
1
ParentImageeq
./runc
1
ParentImageeq
/opt/gitlab/embedded/bin/bundle
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 4 rules

Elastic 4 rules

Splunk 2 rules