To read a compressed source file data area in a download-dense Excel table

3.2 Detection algorithm in the extraction of the secret table, read the compressed source file data area all records (with the beginning of the record 04034b50 as a reference), and the compressed source file directory area records as a match, in the compressed source file directory area to add missing source file directory records, Modify the source file directory to end the relevant information, you can implement the secret form in the Excel table in the normal display and open use. The algorithm 2 is described as follows: Algorithm 2 general form information detection algorithm input the hidden Excel form output secret form STEP1 open Excel table, extract compressed source file data area and directory area all records.

STEP2 in the new Excel table, delete the record of the secret table in the compressed source file directory area.

STEP3 modifies the relevant information in the compression source file directory end flag, including compressing the total number of source file directory records, the size of the catalog area, and generating a loaded Excel table.

If you want to hide multiple secret tables, you can loop through STEP2 and STEP3.

Step2 according to the one by one correspondence principle, compares compresses the source file data area and the directory area record, to the data area appears but the directory area does not appear the source file, according to the catalogue records the data format, to its encoding, produces the corresponding directory area record, adds to the compressed source file data Directory area.

STEP3 modifies the relevant information in the compression source file directory end flag, including the total number of compressed source file directory records, the size of the directory area and the offset of the directory area in the file, generating a new Excel table, which is visible at this time.

If more than one secret form is detected, you can loop through STEP2 and Step3 to show them individually.