An import module may log Chain of Custody error, similar as following:
2015-10-01 13:36:32Z|2712| 46| INFO| CheckHash|***** Chain of Custody Alert. Target MD5-Hash is 91db0662eeb081fdfd67670e213922d7 instead of a9a2edb5dbb3e8a081875ad82be9ac19 | File: \\HOSTNAME\StagingArea\LinkID\ContainerId\ContainerMappingID\ItemId 2015-10-01 13:36:32Z|2712| 46| INFO| CheckHash|***** Aborting Import. Retry handled by core.
The most likely the cause of this error is in-memory virus scanning on the EV server. If a virus scanner touches already exported item, new hash does not correspond with the expected one and a Chain of Custody alert is created during the import.
To avoid this