5 THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE UNAUDITED FINANCIAL STATEMENTS OF NETWORK-1 SECURITY SOLUTIONS, INC. FOR THE PERIOD ENDED SEPTEMBER 30, 2000 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. 9-MOS DEC-31-2000 JAN-01-2000 SEP-30-2000 5,896,000 0 413,000 59,000 18,000 6,401,000 612,000 177,000 7,579,000 1,130,000 0 0 2,000 64,000 5,540,000 7,579,000 775,000 890,000 52,000 345,000 4,222,000 25,000 1,567,000 (5,026,000) 0 (5,026,000) 2,154,000 0 0 (2,872,000) (0.49) (0.49)