@harsvp – Your WD 1 TB HDD has developed uncorrectable sectors. What this in a way means is that firmware tried to relocate them but finally gave up. They may never be corrected and if it contained any data, it’s gone.
Current pending sector count may be reversible after a full low-level format, if it’s a soft error.
Data destructive operation. You may try that. I have successfully restored current pending sector count after a low-level format on some of my HDDs.
The HDD cannot be relied upon anymore. It may remain the same for another year or may fail abruptly. It’s unpredictable. You can use it as non-essential storage. For next few weeks keep closely monitoring it and then take a call.
Just check if any of the WD utilities from below link can help you to analyze it further or check the SMART attributes or do a low-level format.
*support-en.wd.com/app/products/downloads/softwaredownloads