Contact form errors - are these hacker trying to spam people from our websites?

Log Name: Application
Source: ASP.NET 4.0.30319.0
Date: 14/09/2021 17:15:34
Event ID: 1309
Task Category: Web Event
Level: Warning
Keywords: Classic
User: N/A
Computer: server.domain.suffix
Description:
Event code: 3003
Event message: A validation error has occurred.
Event time: 14/09/2021 17:15:34
Event time (UTC): 14/09/2021 16:15:34
Event ID: 906792d9ce9a4cdc94b4526ba7f3d01a
Event sequence: 836
Event occurrence: 5
Event detail code: 0

Application information:
Application domain: /LM/W3SVC/33/ROOT-1-xxx
Trust level: Full
Application Virtual Path: /
Application Path: E:\Websites\www\domain2016\
Machine name: server

Process information:
Process ID: 14260
Process name: w3wp.exe
Account name: IIS APPPOOL\domain2016

Exception information:
Exception type: HttpRequestValidationException
Exception message: A potentially dangerous Request.Form value was detected from the client (messagetext="...ай свои at System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection)
at System.Web.HttpValueCollection.EnsureKeyValidated(String key)
at System.Web.HttpValueCollection.Get(String name)
at System.Web.UI.WebControls.TextBox.LoadPostData(String postDataKey, NameValueCollection postCollection)
at System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.contact_aspx.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)



Request information:
https://www.domain.suffix:443/contact.aspx 
Request path: /contact.aspx
User host address: 178.34.160.12
User:
Is authenticated: False
Authentication Type:
Thread account name: IIS APPPOOL\domain2016

Thread information:
Thread ID: 116
Thread account name: IIS APPPOOL\domain2016
Is impersonating: False
Stack trace: at System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection)
at System.Web.HttpValueCollection.EnsureKeyValidated(String key)
at System.Web.HttpValueCollection.Get(String name)
at System.Web.UI.WebControls.TextBox.LoadPostData(String postDataKey, NameValueCollection postCollection)
at System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.contact_aspx.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)


Custom event details:

Event Xml:



1309
3
3
0x80000000000000

2614200
Application
server.domain.suffix



3003
A validation error has occurred.
14/09/2021 17:15:34
14/09/2021 16:15:34
906792d9ce9a4cdc94b4526ba7f3d01a
836
5
0
/LM/W3SVC/33/ROOT-1-xxx
Full
/
E:\Websites\www\domain2016\
server


14260
w3wp.exe
IIS APPPOOL\domain2016
HttpRequestValidationException
A potentially dangerous Request.Form value was detected from the client (messagetext="...ай свои <a href=https://ussr...").
at System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection)
at System.Web.HttpValueCollection.EnsureKeyValidated(String key)
at System.Web.HttpValueCollection.Get(String name)
at System.Web.UI.WebControls.TextBox.LoadPostData(String postDataKey, NameValueCollection postCollection)
at System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.contact_aspx.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)


https://www.domain.suffix:443/contact.aspx
/contact.aspx
178.34.160.12


False


IIS APPPOOL\domain2016
116
IIS APPPOOL\domain2016
False
at System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection)
at System.Web.HttpValueCollection.EnsureKeyValidated(String key)
at System.Web.HttpValueCollection.Get(String name)
at System.Web.UI.WebControls.TextBox.LoadPostData(String postDataKey, NameValueCollection postCollection)
at System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.contact_aspx.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

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