Reflective Code Loading T1620

Tactic: Stealth

Adversaries may reflectively load code into a process in order to conceal the execution of malicious payloads. Reflective loading involves allocating then executing payloads directly within the memory of the process, vice creating a thread or process backed by a file path on disk (e.g., Shared Modules).

Events covered

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

Authoring guide

Patterns shared across the 12 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 (19 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
event.type5eq 4, ne 1denied, start, allowed, deletion
EventID4eq 2, in 2memory_signature, shellcode_thread, 4104, 7
ScriptBlockText3in 2, match 2, contains 1[reflection.assembly]::load, (?i)[c][r][e][a][t][e][p][r][o][c][e][s][s], (?i)[c][r][e][a][t][e][r][e][m][o][t][e][t][h][r][e][a][d], (?i)[c][r][e][a][t][e][t][h][r][e][a][d], [system.reflection.assembly]::load
host.os.type3eq 3
process_name3eq 2, starts_with 1., kernel, mmc.exe
EventType2eq 2connection_attempted, exec
auditd.data.a22eq 27
auditd.data.syscall2eq 2mprotect
event.category2eq 2process
event.kind2eq 2alert
event.outcome2eq 2failure, success
CommandLine1contains 1afsacgblagyabablagmadabpag8abgauageacwbzaguabqbiagwaeqbda..., awwbyaguazgbsaguaywb0agkabwbuac4ayqbzahmazqbtagiabab5af0a..., bafiazqbmagwazqbjahqaaqbvag4algbbahmacwblag0aygbsahkaxqa6...
Image1starts_with 1/boot/, /dev/shm/, /media/
ImageLoaded1in 1*\\jscript.dll, *\\jscript9.dll, *\\vbscript.dll
container.id1starts_with 1?

Top indicator values (88 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
EventIDin
memory_signature
25
EventIDin
shellcode_thread
25
auditd.data.a2eq
7
22
auditd.data.syscalleq
mprotect
22
event.categoryeq
process
2128
event.kindeq
alert
236
event.typeeq
denied
28
event.typeeq
start
2606
CommandLinecontains
afsacgblagyabablagmadabpag8abgauageacwbzaguabqbiagwaeqbdadoaogaoaciatabvageazaaiac
1
CommandLinecontains
awwbyaguazgbsaguaywb0agkabwbuac4ayqbzahmazqbtagiabab5af0aoga6acgaigbmag8ayqbkaciak
1
CommandLinecontains
bafiazqbmagwazqbjahqaaqbvag4algbbahmacwblag0aygbsahkaxqa6adoakaaiaewabwbhagqaigapa
1
CommandLinecontains
bafiazqbmagwazqbjahqaaqbvag4algbbahmacwblag0aygbsahkaxqa6adoatabvageazaaoa
1
CommandLinecontains
bahiazqbmagwazqbjahqaaqbvag4algbhahmacwblag0aygbsahkaxqa6adoatabvageazaaoa
1
CommandLinecontains
bbahiazqbmagwazqbjahqaaqbvag4algbhahmacwblag0aygbsahkaxqa6adoakaaiaewabwbhagqaigap
1
CommandLinecontains
sacgblagyabablagmadabpag8abgauageacwbzaguabqbiagwaeqbdadoaogbmag8ayqbkacga
1
CommandLinecontains
saugblagyabablagmadabpag8abgauaeeacwbzaguabqbiagwaeqbdadoaogaoaciatabvageazaaiacka
1
CommandLinecontains
saugblagyabablagmadabpag8abgauaeeacwbzaguabqbiagwaeqbdadoaogbmag8ayqbkacga
1
CommandLinecontains
wwbsaguazgbsaguaywb0agkabwbuac4aqqbzahmazqbtagiabab5af0aoga6acgaigbmag8ayqbkaciakq
1
CommandLinecontains
wwbsaguazgbsaguaywb0agkabwbuac4aqqbzahmazqbtagiabab5af0aoga6aewabwbhagqaka
1
CommandLinecontains
wwbyaguazgbsaguaywb0agkabwbuac4ayqbzahmazqbtagiabab5af0aoga6aewabwbhagqaka
1
EventIDeq
4104
1268
EventIDeq
7
139
EventTypeeq
connection_attempted
125
EventTypeeq
exec
1171
Imagestarts_with
/boot/
110
Imagestarts_with
/dev/shm/
123
Imagestarts_with
/media/
14
Imagestarts_with
/mnt/
12
Imagestarts_with
/run/
18
Imagestarts_with
/tmp/
125

Exclusions (23 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
/usr/sbin/apache2
1
Imagein
/usr/share/elasticsearch/jdk/bin/java
1
Imagein
/usr/share/kibana/node/bin/node
1
dest_ipcidr_match
127.0.0.0/8
1
dest_ipcidr_match
169.254.0.0/16
1
dest_ipcidr_match
224.0.0.0/4
1
dest_ipcidr_match
::1
1
process_nameeq
brave
1
process_nameeq
code
1
process_nameeq
deno
1
process_nameeq
dotnet
1
process_nameeq
github-desktop
1
process_nameeq
httpd
1
process_nameeq
java
1
process_nameeq
node
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 2 rules

Elastic 8 rules

Splunk 2 rules