Common fault on many computers, notably HP Pavilions and Compaq PCs and laptops. Avira can falsely detect the APPL/KillApplicat.A and APPL/KillApp.A virus. The problem stems from HP’s recovery partition (generally located on d:\) where those files are an integral part of the recovery procedure.
Do not allow Avira to Quarantine or delete these files. If you have already quarantined them then restore them back to their original location, rescan them and mark as ‘Ignore’.
If you have not already done so, it is good practice to create a set of recovery discs for your computer in case the recovery partition is damaged.