Moody downgrades our local banks

‘International credit rating agency Moody’s has downgraded the outlook
for three Singapore banks – DBS, OCBC and UOB – to “negative” from
“stable” for the next 12-18 months.’ Quoted from TRE.
 
Big, strong and friendly banks with triple A ratings are now rated as
negative? What does it mean? How is this equated to the A, B and C
rating scale? Are our banks now in the B grade or C grade?