A firm$$s computer systems are flooded with thousands of seemingly legitimate requests, the sheer volume of which will slow or shut down the site$$s use. This might be caused by receiving spam from thousands of difficult$-$to$-$shut$-$down accounts. This is an example of

a$.$

Cash$-$out fraudster

b$.$

Data harvester

c$.$

Stealing financial data

d$.$

Malware Attacks

e$.$

DDoS attack