4.9.1 Circumstances for Revocation
Comodo may revoke a digital Certificate if any of the following occur:
A personal identification number, Private Key or password has, or is likely to become known to someone not authorized to use it, or is being or is likely to be used in an unauthorized way
https://www.comodo.com/repository/Comodo_CA_CPS_4.1.4.pdf
4.9.1 Circumstances for Revocation Comodo may revoke a digital Certificate if any of the following occur:
A personal identification number, Private Key or password has, or is likely to become known to someone not authorized to use it, or is being or is likely to be used in an unauthorized way