Exfiltration Over Alternative Protocol T1048

Adversaries may steal data by exfiltrating it over a different protocol than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.

Events covered

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

Authoring guide

Patterns shared across the 47 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 (29 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
CommandLine25contains 11, match 7, regex_match 7, in 2(?i)(davclnt.dll.*DavSetCookie.*://\d{1,3}\.\d{1,3}\.\d{1..., (?i)\s--(form|upload-file|data)\s|\s--data-, (?i)ftp\s+(.{1,})?\-s\:.{1,}\.\w{2,5}, \s-[dTF]\s, (?i)\s+(((copy|move|moveto|copyto)\s+.*\S+:\S+\s+.*\S+:\S...
EventID19eq 194688, 1, 4104, 4103, 3
Image10ends_with 10, contains 3, starts_with 2\rundll32.exe, \winscp.exe, :\program files (x86)\avast software\secureline vpn\, :\program files (x86)\proton technologies\protonvpntap\installer\, :\program files\avast software\secureline vpn\
process_name9eq 5, match 4(?i)\x5ccurl\.exe, (?i)rclone, nslookup.exe, rundll32.exe, rclone.exe
OriginalFileName8eq 8rundll32.exe, winscp.exe, bcp.exe, bitsadmin.exe, cmd.exe
Type8eq 8
ScriptBlockText4contains 3, match 1 -d , -doh , -i , -source, .send(
DestinationPort2eq 1, ne 10, 25, 2525, 465
ParentImage2ends_with 2\svchost.exe
event.type2eq 2creation, start
file_name2eq 2bitsadmin.exe, powershell.exe
parent_process_name2eq 2powershell.exe, svchost.exe
EventData1contains 1-source, ftp://, http://
ImagePath1contains 1tap0901
Initiated1eq 1true

Top indicator values (197 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
EventIDeq
4688
8312
EventIDeq
1
6232
EventIDeq
4104
5268
EventIDeq
4103
3105
CommandLinematch
(?i)\s--(form|upload-file|data)\s|\s--data-
33
CommandLinematch
\s-[dTF]\s
33
CommandLinematch
(?i)\s+(((copy|move|moveto|copyto)\s+.*\S+:\S+\s+.*\S+:\S+)|(serve\s+(dlna|ht...
22
CommandLineregex_match
(?i)(davclnt.dll.*DavSetCookie.*://\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})
33
CommandLineregex_match
(?i)ftp\s+(.{1,})?\-s\:.{1,}\.\w{2,5}
33
CommandLinecontains
/transfer
22
CommandLinecontains
c:\windows\system32\davclnt.dll,davsetcookie
23
CommandLinecontains
-r
16
CommandLinecontains
b2:
1
CommandLinecontains
cp
18
CommandLinecontains
gs:
1
CommandLinecontains
init
1
CommandLinecontains
mi
13
CommandLinecontains
move-item
1
CommandLinecontains
mv
14
CommandLinein
*\\windows\\system32\\davclnt.dll,*davsetcookie*
22
CommandLinein
*\\windows\\syswow64\\davclnt.dll,*davsetcookie*
22
Imageends_with
\rundll32.exe
2103
Imageends_with
\winscp.exe
23
OriginalFileNameeq
rundll32.exe
262
OriginalFileNameeq
winscp.exe
22
ParentImageends_with
\svchost.exe
214
process_nameeq
nslookup.exe
26
process_nameeq
rundll32.exe
255
process_namematch
(?i)\x5ccurl\.exe
22
process_namematch
(?i)rclone
22

Exclusions (47 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
process_namematch
(?i)(cmd|powershell).exe
2
CommandLinecontains
://10.
1
CommandLinecontains
://127.
1
CommandLinecontains
://169.254.
1
CommandLinecontains
://172.16.
1
CommandLinecontains
://172.17.
1
CommandLinecontains
://172.18.
1
CommandLinecontains
://172.19.
1
CommandLinecontains
://172.20.
1
CommandLinecontains
://172.21.
1
CommandLinecontains
://172.22.
1
CommandLinecontains
://172.23.
1
CommandLinecontains
://172.24.
1
CommandLinecontains
://172.25.
1
CommandLinecontains
://172.26.
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.

Sigma 18 rules

Elastic 2 rules

Splunk 24 rules

Kusto 3 rules