Windows Process Injection into Commonly Abused Processes
Description
The following analytic detects process injection into executables that are commonly abused using Sysmon EventCode 10. It identifies suspicious GrantedAccess requests (0x40 and 0x1fffff) to processes such as notepad.exe, wordpad.exe and calc.exe, excluding common system paths like System32, Syswow64, and Program Files. This behavior is often associated with the SliverC2 framework by BishopFox. Monitoring this activity is crucial as it may indicate an initial payload attempting to execute malicious code. If confirmed malicious, this could allow attackers to execute arbitrary code, potentially leading to privilege escalation or persistent access within the environment.
Query · spl
`sysmon`
EventCode=10
TargetImage IN (
"*\\backgroundtaskhost.exe",
"*\\calc.exe",
"*\\CalculatorApp.exe",
"*\\chrome.exe",
"*\\dllhost.exe",
"*\\edge.exe",
"*\\firefox.exe",
"*\\lsass.exe",
"*\\mspaint.exe",
"*\\notepad.exe",
"*\\regsvr32.exe",
"*\\searchprotocolhost.exe",
"*\\spoolsv.exe",
"*\\svchost.exe",
"*\\werfault.exe",
"*\\win32calc.exe",
"*\\wordpad.exe",
"*\\wuauclt.exe"
)
NOT SourceImage IN (
"*:\\Windows\\Program Files (x86)\\*",
"*:\\Windows\\Program Files\\*",
"*:\\Windows\\System32\\*",
"*:\\Windows\\SysWOW64\\*"
)
GrantedAccess IN (
"0x1f3fff",
"0x1fffff",
"0x40"
)
| stats values(user) as user
min(_time) as firstTime
max(_time) as lastTime count
by dest user_id parent_process_name parent_process_guid
process_name process_guid process_id signature SourceImage
TargetImage GrantedAccess CallTrace
| eval CallTrace=split(CallTrace, "|")
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| table firstTime lastTime dest user_id parent_process_name parent_process_guid process_name process_guid process_id signature SourceImage TargetImage GrantedAccess CallTrace
| `windows_process_injection_into_commonly_abused_processes_filter`
Implementation guide
To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.
Known false positives
- False positives may be present based on SourceImage paths, particularly those with a legitimate reason for accessing lsass.exe or regsvr32.exe. If removing the paths is important, realize svchost and many native binaries inject into processes consistently. Restrict or tune as needed.
Analyst notes
Known false positives: False positives may be present based on SourceImage paths, particularly those with a legitimate reason for accessing lsass.exe or regsvr32.exe. If removing the paths is important, realize svchost and many native binaries inject into processes consistently. Restrict or tune as needed.