It is possible to capture groups from the regular expression and log them into the
alert events.
-There is 3 capabilities:
+There are 3 capabilities:
* pkt: the extracted group is logged as pkt variable in ``metadata.pktvars``
-* alert: the extracted group is logged to the ``alert.extra`` subobject
+* alert: the extracted group is logged to the ``alert.context`` subobject
* flow: the extracted group is stored in a flow variable and end up in the ``metadata.flowvars``
To use the feature, parameters of pcre keyword need to be updated.
-After the regular pcre regex and options, a comma separated lists of variable names.
+After the regular pcre regex and options, a comma-separated list of variable names.
The prefix here is ``flow:``, ``pkt:`` or ``alert:`` and the names can contain special
characters now. The names map to the capturing substring expressions in order ::
flow:ua/ubuntu/repo,flow:ua/ubuntu/pkg/base, \
flow:ua/ubuntu/pkg/version";
-This would result in the alert event has something like ::
+This would result in the alert event having something like ::
"metadata": {
"flowvars": [
With that syntax, the result of the extraction will appear like ::
"alert": {
- "extra": {
+ "context": {
"ua/ubuntu/repo": "fr",
"ua/ubuntu/pkg/base": "curl",
"ua/ubuntu/pkg/version": "2.2.1"