Detection rules › Sigma
Microsoft IIS Connection Strings Decryption
Detects use of aspnet_regiis to decrypt Microsoft IIS connection strings. An attacker with Microsoft IIS web server access via a webshell or alike can decrypt and dump any hardcoded connection strings, such as the MSSQL service account password using aspnet_regiis command.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Credential Access | T1003 OS Credential Dumping |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 1 | Process creation |
Stages and Predicates
Stage 1: all of selection_name
or:
Image|endswith: '\aspnet_regiis.exe'
OriginalFileName: aspnet_regiis.exe
Stage 2: all of selection_args
CommandLine|contains: ' -pdf'
CommandLine|contains: connectionStrings
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.
| Field | Kind | Values |
|---|---|---|
CommandLine | match |
|
Image | ends_with |
|
OriginalFileName | eq |
|