Detection rules › Splunk

Wermgr Process Connecting To IP Check Web Services

Author
Teoderick Contreras, Mauricio Velazco, Splunk
Source
upstream

The following analytic detects the wermgr.exe process attempting to connect to known IP check web services. It leverages Sysmon EventCode 22 to identify DNS queries made by wermgr.exe to specific IP check services. This activity is significant because wermgr.exe is typically used for Windows error reporting, and its connection to these services may indicate malicious code injection, often associated with malware like Trickbot. If confirmed malicious, this behavior could allow attackers to recon the infected machine's IP address, aiding in further exploitation and evasion tactics.

MITRE ATT&CK coverage

TacticTechniques
ReconnaissanceT1590.005 Gather Victim Network Information: IP Addresses

Event coverage

ProviderEvent IDTitle
Sysmon22DNSEvent (DNS query)

Stages and Predicates

Stage 1: search

search EventCode=22 QueryName IN ("*api.ip.sb", "*api.ipify.org", "*b.barracudacentral.org", "*cbl.abuseat.org", "*checkip.amazonaws.com", "*dnsbl-1.uceprotect.net", "*icanhazip.com", "*ip.anysrc.com", "*ipecho.net", "*ipinfo.io", "*spam.dnsbl.sorbs.net", "*wtfismyip.com", "*zen.spamhaus.org", "ident.me", "www.myexternalip.com") process_name="wermgr.exe"

Stage 2: stats

stats BY answer, answer_count, dvc, process_exec, process_guid, process_name, query, query_count, reply_code_id, signature, signature_id, src, user_id, vendor_product, QueryName, QueryResults, QueryStatus

Stage 3: search

search

Stage 4: search

search

Stage 5: search

search `macro`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 22 corpus 15 (splunk 15)
QueryNamein
  • "*api.ip.sb" corpus 2 (splunk 2)
  • "*api.ipify.org" corpus 2 (splunk 2)
  • "*b.barracudacentral.org" corpus 2 (splunk 2)
  • "*cbl.abuseat.org" corpus 2 (splunk 2)
  • "*checkip.amazonaws.com"
  • "*dnsbl-1.uceprotect.net" corpus 2 (splunk 2)
  • "*icanhazip.com" corpus 2 (splunk 2)
  • "*ip.anysrc.com" corpus 2 (splunk 2)
  • "*ipecho.net" corpus 2 (splunk 2)
  • "*ipinfo.io" corpus 2 (splunk 2)
  • "*spam.dnsbl.sorbs.net" corpus 2 (splunk 2)
  • "*wtfismyip.com" corpus 2 (splunk 2)
  • "*zen.spamhaus.org" corpus 2 (splunk 2)
  • "ident.me" corpus 2 (splunk 2)
  • "www.myexternalip.com" corpus 2 (splunk 2)
process_nameeq
  • wermgr.exe