↳ GitHub sourceAnalytics ruleHigh
Identify SysAid Server web shell creation
Description
'This query looks for potential webshell creation by the threat actor Mercury after the sucessful exploitation of SysAid server.
Reference: https://www.microsoft.com/security/blog/2022/08/25/mercury-leveraging-log4j-2-vulnerabilities-in-unpatched-systems-to-target-israeli-organizations/'
- Rule type
- Scheduled
- Version
- 1.0.3
- Query frequency
- 1d
- Query period
- 1d
- Trigger
- gt 0
Declared MITRE coverage
Declared sources
Metadata from the source file. No dependencies inferred from KQL.
Connectors
Data types
KQL query
Original query, unchanged.
let timeframe = 1d;
let time_window = 5m;
(union isfuzzy=true
(SecurityEvent
| where TimeGenerated > ago(timeframe)
| where EventID == 4688
| where Process has_any ("java.exe", "javaw.exe") and CommandLine has "SysAidServer"
| summarize by ParentProcessName,Process, Account, Computer, CommandLine, timekey= bin(TimeGenerated, time_window), TimeGenerated, SubjectLogonId
| join kind=inner(
SecurityEvent
| where TimeGenerated > ago(timeframe)
| where EventID == 4663
| where Process has_any ("java.exe", "javaw.exe")
| where AccessMask in ('0x2','0x100', '0x10', '0x4')
| where ObjectName endswith ".jsp"
| summarize by ParentProcessName, Account, Computer, ObjectName, ProcessName, timekey= bin(TimeGenerated, time_window), TimeGenerated, SubjectLogonId)
on timekey, Computer, SubjectLogonId
),
(DeviceFileEvents
| where InitiatingProcessFileName has_any ("java.exe", "javaw.exe")
| where InitiatingProcessCommandLine has "SysAidServer"
| where FileName endswith ".jsp"
| extend Account = strcat(InitiatingProcessAccountDomain, @'\', InitiatingProcessAccountName), Computer = DeviceName
),
(imFileEvent
| where TimeGenerated > ago(timeframe)
| where EventType == "FileCreated"
| where ActingProcessName has_any ("java.exe", "javaw.exe")
| where ActingProcessCommandLine has "SysAidServer"
| where FilePath endswith ".jsp"
| extend Account = ActorUsername, Computer = DvcHostname
)
)
| extend AccountName = tostring(split(Account, @'\')[1]), AccountNTDomain = tostring(split(Account, @'\')[0])
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
Declared entities
Related content
Links established from declared identifiers and solution manifests.
Source provenance
GitHubDisplayed values come from files in Azure/Azure-Sentinel. They describe the published template, not your workspace configuration.
- Commit
9800e51↗- Source identifier
50eb4cbd-188f-44f4-b964-bab84dcdec10
GSTEP / CATALOG TRACKING
Added to catalog : 16 Sept 2026 · 05:49 UTC
Last change observed : 16 Sept 2026 · 05:49 UTC