Exfiltration Over Alternative Protocol T1048

Tactic: Exfiltration

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

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

Authoring guide

Patterns shared across the 118 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 (134 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
CommandLine28contains 14, match 9, regex_match 7, in 2, wildcard 1(?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...
EventID23eq 234688, 1, 4104, 4103, FileDownloaded
process_name16eq 8, in 4, match 4(?i)\x5ccurl\.exe, (?i)rclone, nslookup.exe, rundll32.exe, bash
Image11ends_with 11, contains 4, starts_with 2\rundll32.exe, \winscp.exe, /python, /python2, /python2.
EventType10eq 6, in 5exec, ProcessRollup2, exec_event, ConnectionEvent, FileBlocked
Type9eq 9account, ip
event.type9eq 9start, creation
OriginalFileName8eq 8rundll32.exe, winscp.exe, bcp.exe, bitsadmin.exe, cmd.exe
sourcetype7eq 7stream:http, cisco:asa, cisco:sfw:estreamer, gsuite:gmail:bigquery, o365:management:activity
DataSource6eq 6OUTBOUND_SMTP_MAIL, RAL_DATA, SAST_DO, SE16N_CHANGEDOCS, SLG1_ODATA
NetworkApplicationProtocol6eq 5, in 1SMTP, HTTP, HTTPs
host.os.type6eq 6
DestinationPort5eq 2, in 2, ne 1139, 445, 0, 25, 2525
DstPortNumber5eq 2, in 2, ne 13389, 20, 21, 22, 23
inspected_document5is_not_null 5

Top indicator values (640 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
8313
EventIDeq
1
6237
EventIDeq
4104
5268
EventIDeq
4103
3105
EventIDeq
FileDownloaded
22
event.typeeq
start
8606
EventTypein
ProcessRollup2
4117
EventTypein
exec
4171
EventTypein
exec_event
4139
EventTypein
start
4134
EventTypein
executed
388
EventTypein
process_started
374
NetworkApplicationProtocoleq
SMTP
44
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
CommandLinematch
.*[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}.*
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
EventTypeeq
exec
3171
Protocoleq
tcp
318
SubjectUserNameeq
anonymous
33
CommandLinecontains
/transfer
22
CommandLinecontains
c:\windows\system32\davclnt.dll,davsetcookie
23
CommandLinecontains
http:
25
CommandLinecontains
https:
25
CommandLinein
*\\windows\\system32\\davclnt.dll,*davsetcookie*
22
CommandLinein
*\\windows\\syswow64\\davclnt.dll,*davsetcookie*
22
DestinationPortin
139
24
DestinationPortin
445
27

Exclusions (127 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_ipin
10.0.0.0/8
3
dest_ipin
172.16.0.0/12
3
dest_ipin
192.168.0.0/16
3
dest_ipin
100.64.0.0/10
2
dest_ipin
127.0.0.0/8
2
dest_ipin
169.254.0.0/16
2
dest_ipin
192.0.0.0/24
2
dest_ipin
192.0.0.0/29
2
dest_ipin
192.0.0.10/32
2
d_domaineq
corp_domain
2
dest_ipcidr_match
10.0.0.0/8
2
dest_ipcidr_match
127.0.0.0/8
2
dest_ipcidr_match
169.254.0.0/16
2
dest_ipcidr_match
172.16.0.0/12
2
dest_ipcidr_match
192.168.0.0/16
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 24 rules

Elastic 17 rules

Splunk 33 rules

Kusto 37 rules

YARA-L 4 rules

Panther 3 rules