ATT&CK coverage › Technique

Web Service T1102

Adversaries may use an existing, legitimate external Web service as a means for relaying data to/from a compromised system. Popular websites, cloud services, and social media acting as a mechanism for C2 may give a significant amount of cover due to the likelihood that hosts within a network are already communicating with them prior to a compromise. Using common services, such as those offered by Google, Microsoft, or Twitter, makes it easier for adversaries to hide in expected noise. Web service providers commonly use SSL/TLS encryption, giving adversaries an added level of protection.

Events covered

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

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon3Network connection
Sysmon22DNSEvent (DNS query)
Security-Auditing4688A new process has been created.

Authoring guide

Patterns shared across the 14 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized 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 (9 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
DestinationHostname8ends_with 4, match 4.localto.net, .localtonet.com, tunnel.in.ngrok.com, tunnel.sa.ngrok.com, tunnel.au.ngrok.com
Image6ends_with 6, eq 5, starts_with 4, match 3, is_null 3C:\Program Files\Mozilla Firefox\firefox.exe, \WindowsApps\MicrosoftEdge.exe, C:\Program Files (x86)\Google\Chrome\Application\chrome.exe, \MsSense.exe, C:\Program Files\Falkon\
Initiated4eq 4true
CommandLine3match 3 tunnel , cleanup , -connector-id , run , -credentials-contents
DnsQuery1is_not_null 1, match 1NgrokDomains
ParentImage1match 1\ManageEngine\ServiceDesk\, \java.exe
dns.question.name1in 1"*.ngrok.io", "*.ngrok.com", "korgn.*.lennut.com"
QueryName1in 1"*cdn.discordapp.com*", "*storjshare.io*", "*hastebin.com*"
EventID1eq 122

Top indicator values (245 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.

FieldKindValueRules (here)Corpus reach
Imageends_with\seamonkey.exe513
Imageends_with\safari.exe512
Imageends_with\opera.exe521
Imageends_with\msedge.exe522
Imageends_with\brave.exe520
Imageends_with\maxthon.exe513
Imageends_with\vivaldi.exe519
Imageends_with\WindowsApps\MicrosoftEdge.exe512
Imageends_with\whale.exe512
Imageends_with\msedgewebview2.exe515
Initiatedeqtrue440
Imagestarts_withC:\Program Files (x86)\Microsoft\EdgeCore\411
ImageeqC:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe411
Imagestarts_withC:\Program Files (x86)\Microsoft\EdgeWebView\Application\410
Imagestarts_withC:\Program Files\Microsoft\EdgeCore\411
ImageeqC:\Program Files\Google\Chrome\Application\chrome.exe412
ImageeqC:\Program Files (x86)\Internet Explorer\iexplore.exe410
ImageeqC:\Program Files (x86)\Mozilla Firefox\firefox.exe411
ImageeqC:\Program Files\Mozilla Firefox\firefox.exe412
ImageeqC:\Program Files\Internet Explorer\iexplore.exe411

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 11 rules

Splunk 2 rules

Kusto Query Language 1 rule