User Execution: Malicious Link T1204.001

Tactic: Execution

An adversary may rely upon a user clicking a malicious link in order to gain execution. Users may be subjected to social engineering to get them to click on a link that will lead to code execution. This user action will typically be observed as follow-on behavior from Spearphishing Link. Clicking on a link may also lead to other execution techniques such as exploitation of a browser or application vulnerability via Exploitation for Client Execution. Links may also lead users to download files that require execution via Malicious File.

Events covered

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

Authoring guide

Patterns shared across the 16 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 (27 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
EventID5eq 4, in 11, 3, 4688, 5156, Campaign
process_name3match 2, eq 1(?i)outlook\.exe, powershell.exe, powershell_ise.exe, pwsh.exe
CommandLine2contains 2, eq 1, in 1#, *-w*h*, *DownloadString*, *Invoke-Expression*, account
DestinationPort2match 2^445$
ParentImage2ends_with 2/script editor, \explorer.exe
parent_process_name2match 2(?i)(Microsoft..., (?i)(Microsoft...
Details1contains 1%comspec%, account, anti-bot
DeviceEventClassID1eq 1MaliciousUrlDetected
DeviceVendor1eq 1Acronis
EventType1eq 1authorize, copy
Image1contains 1, ends_with 1/bash, /chmod, /curl
OriginalFileName1eq 1powershell.exe, powershell_ise.exe, pwsh.dll
TargetFilename1contains 1\\microsoft\\windows\\recent\\
TargetObject1contains 1\software\microsoft\windows\currentversion\explorer\runmru\
ThreatTypes1ne 1

Top indicator values (140 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
DestinationPortmatch
^445$
22
process_namematch
(?i)outlook\.exe
22
CommandLinecontains
#
13
CommandLinecontains
account
12
CommandLinecontains
anti-bot
12
CommandLinecontains
botcheck
12
CommandLinecontains
captcha
12
CommandLinecontains
challenge
12
CommandLinecontains
clipboard
12
CommandLinecontains
confirmation
12
CommandLinecontains
decode
15
CommandLinecontains
fraud
12
CommandLinecontains
frombase64string
112
CommandLinecontains
human
12
CommandLinecontains
identification
12
CommandLinecontains
identificator
12
CommandLinecontains
identity
12
CommandLinecontains
iex
16
CommandLinecontains
robot
12
CommandLinecontains
validation
12
CommandLinecontains
verification
12
CommandLinecontains
verify
12
CommandLineeq
*-w*h*
1
CommandLinein
*DownloadString*
1
CommandLinein
*Invoke-Expression*
12
CommandLinein
*Invoke-WebRequest*
13
CommandLinein
*Net.WebClient*
1
CommandLinein
*[Convert]::FromBase64String*
1
CommandLinein
*bot*
1
CommandLinein
*captcha*
1

Exclusions (1 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
dest_ipmatch
^(10\.|172\.(1[6-9]|2[0-9]|3[0-1])\.|192\.168\.|fc00:|fd00:|fe80:)
2

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 3 rules

Splunk 6 rules

Kusto 2 rules

Panther 1 rule