Hello Carl,
the severity should be 6 and you can see it with sh log locally on device
example:
Jun 8 11:49:24 MEST: %SEC-6-IPACCESSLOGP: list anti-sasser permitted udp 10.106.208.183(1320) -> 192.168.1.2(53), 1 packet
or on the syslog server if configured
Hope to help
Giuseppe