Lost .CR2 files while tranferring to PC from SD card.

Hi all,
While transferring the CR2 (Canon RAW) files ( shot by Canon 70D) from Sandisk Extreme Pro 32 GB SDHC card to computer HDD via a card reader, about 500-550 files got lost. Lost in the sense although their volume is still being shown in the SD card, but the their numbers are not being shown there e.g. the file numbering are shown as 9295….then next one is 9967.So 672 nos. files are missing. Out of this I have probably deleted around 100-150 images on field, the rest should have been shown on the card.

In all probability--due to virus attack, even though a paid ‘anti virus’ is installed in my PC.

Please suggest me what would be the best way to get them back. They contain very important images for me.

Rgds

http://kb.sandisk.com/​app/answers/detail/a_i​d/4985

Reservoir Dog wrote in post #17364715
http://kb.sandisk.com/​app/answers/detail/a_i​d/4985

Finally the lost files (cr2) recovered using the bundled 'Rescue Pro Deluxe' software.

Thanks

PIXPHATIC wrote in post #17364704
In all probability--due to virus attack, even though a paid ‘anti virus’ is installed in my PC.

Glad you recovered your images. But, as someone technically orientated and very computer literate enlighten me as to why you think a virus "In all probability" the cause?