For each word in a dictionary, all possible combinations of upper- and lower-case variants are generated.
This attack was implemented as a stand-alone attack mode in hashcat-legacy. In hashcat we emulate this attack with a much more efficient ruleset. The information for this section has moved to a dedicated wiki article available here Using rules to emulate toggle attack.
If our dictionary contains the word
Hashcat creates the following password candidates
pass1234 Pass1234 pAss1234 PAss1234 paSs1234 PaSs1234 pASs1234 PASs1234 pasS1234 PasS1234 pAsS1234 PAsS1234 paSS1234 PaSS1234 pASS1234 PASS1234