Here is the information for the office hours:

Engin Kirda:

Tuesdays, 3pm-4pm, 617 ISEC

Prashant:

Tuesdays (4-6pm), Zoom: https://northeastern.zoom.us/j/9660036397
Fridays (4-6pm), Zoom: https://northeastern.zoom.us/j/9660036397

Bahruz:

Mondays (2-4pm), Zoom: https://northeastern.zoom.us/j/93415672653
Wednesdays (2-4pm), ISEC 655B

Also, feel free to post questions on Piazza -- we will be monitoring.