Scheduled Task/Job: At T1053.002

Tactics: Execution, Persistence, Privilege Escalation

Adversaries may abuse the at utility to perform task scheduling for initial or recurring execution of malicious code. The at utility exists as an executable within Windows, Linux, and macOS for scheduling tasks at a specified time and date. Although deprecated in favor of Scheduled Task's schtasks in Windows environments, using at requires that the Task Scheduler service be running, and the user to be logged on as a member of the local Administrators group. In addition to explicitly running the `at` command, adversaries may also schedule a task with at by directly leveraging the Windows Management Instrumentation `Win32_ScheduledJob` WMI class.

Events covered

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

Authoring guide

Patterns shared across the 18 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 (30 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
CommandLine4contains 3, in 1, wildcard 1* nc *, * nc.traditional *, * ncat *, */etc/at.allow, */etc/at.deny
EventType4in 3, eq 1creation, rename, ProcessRollup2, exec, exec_event
event.type4eq 3, ne 1start, change, deletion
process_name4eq 3, in 2at.exe, at, atd, ctl, docker
EventLog3eq 3RPCFW
InterfaceUuid3eq 31ff70682-0a51-30e8-076d-740be8cee98b, 378e52b0-c0a9-11cf-822d-00aa0051e40f, 86d35949-83c9-4044-b424-db363231fd0c
OpNum3eq 31, 0, 10, 11
TargetFilename3starts_with 2, wildcard 2/boot/efi/efi/*/grub.cfg, /boot/grub/grub.cfg, /boot/grub2/grub.cfg, /etc/*, /etc/cron.allow
host.os.type3eq 3
Image2ends_with 2/at, /atd, \at.exe
process.args2eq 1, in 1, starts_with 1--, --restart=Never, \\, bash
AccessList1contains 1writedata
Details1eq 10x00000001, 1
OriginalFileName1eq 1at.exe
RelativeTargetName1eq 1atsvc

Top indicator values (300 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
EventLogeq
RPCFW
317
OpNumeq
1
33
OpNumeq
0
22
EventTypein
creation
223
EventTypein
rename
218
TargetFilenamewildcard
/etc/cron.allow
23
TargetFilenamewildcard
/etc/cron.d/*
23
TargetFilenamewildcard
/etc/cron.daily/*
23
TargetFilenamewildcard
/etc/cron.deny
23
TargetFilenamewildcard
/etc/cron.hourly/*
23
TargetFilenamewildcard
/etc/cron.monthly/*
23
TargetFilenamewildcard
/etc/cron.weekly/*
23
TargetFilenamewildcard
/etc/crontab
23
TargetFilenamewildcard
/etc/systemd/system/*
24
TargetFilenamewildcard
/home/*/.config/systemd/user/*
24
TargetFilenamewildcard
/home/*/.local/share/systemd/user/*
24
TargetFilenamewildcard
/lib/systemd/system/*
24
TargetFilenamewildcard
/root/.config/systemd/user/*
24
TargetFilenamewildcard
/root/.local/share/systemd/user/*
24
TargetFilenamewildcard
/usr/lib/systemd/system/*
24
TargetFilenamewildcard
/usr/local/lib/systemd/system/*
24
TargetFilenamewildcard
/var/spool/anacron/*
23
TargetFilenamewildcard
/var/spool/cron/atjobs/*
22
TargetFilenamewildcard
/var/spool/cron/crontabs/*
23
event.typeeq
start
2606
process_nameeq
at.exe
23
AccessListcontains
writedata
14
CommandLinecontains
\\\\\\\\
13
CommandLinecontains
echo
18
CommandLinecontains
interactive
13

Exclusions (72 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
file.extensionin
dpkg-remove
2
Imagein
./usr/bin/podman
1
Imagein
/bin/autossl_check
1
Imagein
/bin/chef-client
1
Imagein
/bin/dnf
1
Imagein
/bin/dnf-automatic
1
Imagein
/bin/dockerd
1
Imagein
/bin/dpkg
1
Imagein
/bin/dpkg-divert
1
Imagein
/bin/microdnf
1
Imagein
/bin/pacman
1
Imagein
/bin/pamac-daemon
1
Imagein
/bin/podman
1
Imagein
/bin/puppet
1
Imagein
/bin/rpm
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 8 rules

Elastic 6 rules

Splunk 4 rules