ATT&CK coverage › Technique

System Binary Proxy Execution T1218

Adversaries may bypass process and/or signature-based defenses by proxying execution of malicious content with signed, or otherwise trusted, binaries. Binaries used in this technique are often Microsoft-signed files, indicating that they have been either downloaded from Microsoft or are already native in the operating system. Binaries signed with trusted digital certificates can typically execute on Windows systems protected by digital signature validation. Several Microsoft signed binaries that are default on Windows installations can be used to proxy execution of other files or commands.

Events covered

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

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon3Network connection
Sysmon7Image loaded
Sysmon11FileCreate
Sysmon12RegistryEvent (Object create and delete)
Sysmon13RegistryEvent (Value Set)
Sysmon14RegistryEvent (Key and Value Rename)
Sysmon22DNSEvent (DNS query)
Sysmon29FileExecutableDetected
Security-Auditing4688A new process has been created.
PowerShell4103Payload Context: ContextInfo User Data: UserData.
PowerShell4104Creating Scriptblock text (MessageNumber of MessageTotal).
MsiInstaller1040Beginning a Windows Installer transaction: %0
MsiInstaller1042Ending a Windows Installer transaction: %0

Authoring guide

Patterns shared across the 136 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 (27 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
Image105ends_with 102, match 9, eq 3, starts_with 1\rundll32.exe, \pwsh.exe, \regsvr32.exe, \certutil.exe, \addinutil.exe
CommandLine76match 75, ends_with 3, eq 2, starts_with 1, regex_match 1, is_null 1https://, http://, ftp://, http, -s
OriginalFileName58eq 58AddInUtil.exe, AgentExecutor.exe, PresentationHost.exe, diskshadow.exe, CertOC.exe
ParentImage37ends_with 33, eq 5, starts_with 2, match 1, is_null 1\wsl.exe, \Microsoft.Management.Services.IntuneWindowsAgent.exe, \pcwrun.exe, \provlaunch.exe, \pwsh.exe
TargetFilename8ends_with 7, match 2.dll, .exe, .sed, .rar, .appx
CurrentDirectory4eq 2, is_null 2, match 2c:\windows\system32\, c:\windows\sysWOW64\, C:\Program Files\Windows Defender\Offline\, \Desktop\, \AppData\Local\Temp\
process_name3eq 3rundll32.exe, bitlockertogo.exe, "bitlockertogo.exe"
TargetObject3match 2, ends_with 1Software\Microsoft\Windows..., \Microsoft\Windows NT\CurrentVersion\Accessibility\Configuration, Software\Microsoft\Windows NT\CurrentVersion\Accessibility\ATs, \Software\Microsoft\WAB\DLLPath, \SOFTWARE\Microsoft\Provisioning\Commands\
ImageLoaded3ends_with 2, match 1, starts_with 1\Music\, \AppData\Roaming\, \Contacts\, C:\Windows\System32\, C:\Program Files\Microsoft Silverlight\
ParentCommandLine3match 2, eq 1C:\windows\system32\svchost.exe -k netsvcs -p -s gpsvc, -Embedding, \splash.hta, C:\MEM_Configmgr_, \Program...
Hashes3match 3IMPHASH=d8b52ef6aaa3a81501bdfff9dbb96217, IMPHASH=977eb4c263d384e47daa0712d34713ab, IMPHASH=980fe6cf0d996ab1eedf877222e722aa, IMPHASH=334d66c33503ccbf647c15b47c27eef4, IMPHASH=6834B1B94E49701D77CCB3C0895E1AFD
Details2eq 2(Empty), %CommonProgramFiles%\System\wab32.dll
dest_ip2cidr_match 210.0.0.0/8, ::1/128, fe80::/10, 20.192.0.0/10, 20.184.0.0/13
Company2eq 2, is_null 1Sysinternals - www.sysinternals.com, Sysinternals, Microsoft Corporation
Product2is_null 1, starts_with 1, eq 1Sysinternals, OpenSSH for Windows

Top indicator values (930 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\mshta.exe1357
Imageends_with\cscript.exe1164
Imageends_with\wscript.exe1164
Imageends_with\powershell.exe11143
Imageends_with\cmd.exe1092
Imageends_with\pwsh.exe10140
Imageends_with\regsvr32.exe957
Imageends_with\rundll32.exe976
CommandLinematchhttps://714
CommandLinematchhttp://715
Imageends_with\certutil.exe734
Imageends_with\certoc.exe610
Imageends_with\calc.exe613
CommandLinematchftp://57
CommandLinematchhttp531
CommandLinematch\Users\Public\517
Imageends_with\schtasks.exe545
Imageends_with\CertReq.exe55
Imageends_with\hh.exe514
Imageends_with\addinutil.exe44

Common exclusions (24 distinct)

Field/operator/value combinations that rules under this technique routinely exclude (top-level not() clauses). 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.

FieldKindValueRules excluding
file.nameeqCOMSVCS.DLL1
All_Traffic.dest_ipin"192.0.0.10/32"1
All_Traffic.dest_ipin"198.51.100.0/24"1
All_Traffic.dest_ipin"192.168.0.0/16"1
All_Traffic.dest_ipin"192.0.0.170/32"1
All_Traffic.dest_ipin"192.52.193.0/24"1
All_Traffic.dest_ipin"192.0.0.0/29"1
All_Traffic.dest_ipin"100.64.0.0/10"1
All_Traffic.dest_ipin"127.0.0.0/8"1
All_Traffic.dest_ipin"192.0.0.0/24"1
All_Traffic.dest_ipin"240.0.0.0/4"1
All_Traffic.dest_ipin"10.0.0.0/8"1
All_Traffic.dest_ipin"203.0.113.0/24"1
All_Traffic.dest_ipin"172.16.0.0/12"1
All_Traffic.dest_ipin"192.0.2.0/24"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 132 rules

Elastic 1 rule

Splunk 3 rules