Evolutionary Data Preprocessing to Alleviate Class Imbalance

Table 2

The number of instances after undersampling.

Classes		Instances	# Of instances after undersampling
1	Normal	2,218,764	69,337
2	Exploits	44,525	44,525
3	Reconnaissance	13,987	13,987
4	DoS	16,353	16,353
5	Generic	215,481	53.871
6	Shellcode	1,511	1,511
7	Fuzzers	24,246	24,246
8	Worms	174	174
9	Backdoor	2,329	2,329
10	Analysis	2,677	2,677
Total		2,540,047	229,010

Bold values show the difference in the number of instances before and after undersampling.