Message for specifying an adjustment to the likelihood of a finding as
part of a detection rule.
Increase or decrease the likelihood by the specified number of
levels. For example, if a finding would be POSSIBLE
without the detection rule and relative_likelihood is 1,
then it is upgraded to LIKELY, while a value of -1 would
downgrade it to UNLIKELY. Likelihood may never drop below
VERY_UNLIKELY or exceed VERY_LIKELY, so applying an
adjustment of 1 followed by an adjustment of -1 when base
likelihood is VERY_LIKELY will result in a final
likelihood of LIKELY.
