[word=a] [tag=JJ] [lemma=□] □
[word=a] [tag=JJ] [lemma=computer] □
[word=a] [tag=JJ] [lemma=or] □
The programs can be written to perform malicious tasks after infecting a new computer , or do no more than copy themselves from machine to machine . The problem is that generating large NT rainbow tables is beyond the scale of a single computer , or even a hundred computers .