Develop Capabilities: Malware T1587.001

Tactic: Resource Development

Adversaries may develop malware and malware components that can be used during targeting. Building malicious software can include the development of payloads, droppers, post-compromise tools, backdoors (including backdoored images), packers, C2 protocols, and the creation of infected removable media. Adversaries may develop malware to support their operations, creating a means for maintaining control of remote machines, evading defenses, and executing post-compromise behaviors.

Events covered

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

Authoring guide

Patterns shared across the 13 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 (14 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, wildcard 1 -i -s cmd, -i -s powershell, -i -s pwsh, -p , -u
Image5ends_with 5, contains 2.exe, :\program files (x86)\, :\program files (x86)\microsoft office\, :\program files\, :\program files\common files\microsoft shared\clicktorun\
TargetFilename3contains 3, ends_with 2.docb, .docm, .docx, .exe, .vhd
ParentCommandLine2contains 1, ends_with 1, starts_with 1.exe, @modelcontextprotocol, C:\Windows\SysWOW64\, C:\Windows\System32\, agentgpt
Description1eq 1csexec
EventType1eq 1IntrusionEvent
Impact1in 11, 2
Malware1is_not_null 1, ne 1None
NetflowUsername1is_not_null 1
event.type1eq 1start
parent_process_name1in 1, starts_with 1Cursor Helper, Cursor Helper (Plugin), Jan
process.args1eq 1build
process_name1eq 1, in 1cargo, cl.exe, clang
sourcetype1eq 1cisco:sfw:estreamer

Top indicator values (219 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
CommandLinecontains
accepteula
37
CommandLinecontains
-i -s cmd
22
CommandLinecontains
-i -s powershell
22
CommandLinecontains
-i -s pwsh
22
CommandLinecontains
-s -i cmd
22
CommandLinecontains
-s -i powershell
22
CommandLinecontains
-s -i pwsh
22
CommandLinecontains
-s cmd
22
CommandLinecontains
-s powershell
22
CommandLinecontains
-s pwsh
22
CommandLinecontains
c:\users\
27
CommandLinecontains
paexec
2
CommandLinecontains
psexec
2
CommandLinecontains
-p
110
CommandLinecontains
-u
18
CommandLinecontains
\\\\
18
CommandLinecontains
%windir:~-1,1%
1
CommandLinecontains
%windir:~-3,1%%public:~-9,1%
1
CommandLinecontains
-o
12
CommandLinecontains
.txt
19
CommandLinecontains
/c
115
CommandLinecontains
/e:vbscript
1
CommandLinecontains
/f
17
CommandLinecontains
/tn "security script
1
CommandLinecontains
\\\\127.
1
CommandLinecontains
\\\\localhost
1
CommandLinecontains
\appdata\local\temp\
126
CommandLinecontains
\desktop\
113
CommandLinecontains
del
13
CommandLinecontains
log.txt
1

Exclusions (77 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
CommandLinecontains
\\\\127.
1
CommandLinecontains
\\\\localhost
1
CommandLinecontains
accepteula
1
CommandLinecontains
paexec
1
CommandLinecontains
psexec
1
Imagecontains
:\program files (x86)\
1
Imagecontains
:\program files (x86)\microsoft office\
1
Imagecontains
:\program files\
1
Imagecontains
:\program files\common files\microsoft shared\clicktorun\
1
Imagecontains
:\program files\microsoft office\
1
Imagecontains
:\program files\windows defender\
1
Imagecontains
:\programdata\microsoft\windows defender\
1
Imagecontains
:\windows\microsoft.net\framework
1
Imagecontains
:\windows\microsoft.net\framework64\
1
Imagecontains
:\windows\microsoft.net\framework\
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 1 rule

Splunk 1 rule

Kusto 1 rule