Dealing with a dust bunny

[almcl]

Having a bit of an issue with a brand new and rather intrusive dust bunny which has just appeared on my T5i's sensor (visible just below centre on 4th image below).  It doesn't want to 'blow away' nor yield to my lenspen.

It shows up on the lights (1st image below).  It shows up on the flats (2nd image below) but DSS doesn't remove it in either sigma clip or average mode (3rd image).

Any thoughts on how to deal with this would be very welcome?

Single, unprocessed light frame:

Single, unprocessed flat frame:

The output from DSS, sigma clip mode:

The mark, just visible slightly below centre of sensor:

[Zakalwe]

You might need to get a "wet" cleaner for the sensor. Dust bunnies can get stuck to the sensor and can take some shifting. A PEC pad and some isopropyl should shift it.

 

[xtreemchaos]

you iver need a very small ferret or a cotton bud with some badder wonder fluid on it, I do my cam about every 6 months, I don't know where thay come from. charl. ps I think wonder fluid has antistatic propertys because I get few dustys since I started using it..

[Ibbo!]

A small nuclear warhead usually sorts them ??

 

or this type of thing

https://www.ebay.co.uk/itm/6-PCS-CMOS-CCD-Cleaner-15mm-Wet-SWAB-Sensor-Cleaning-Kit-for-Camera-UK-SELLER/192136113361?epid=8007137795&hash=item2cbc346cd1:g:AosAAOSwX~dWtKqn

[almcl]

Thanks everyone for the thoughts.

I should perhaps have mentioned that I tried these but so far, without managing to shift the offending item.  

It may well be that Juan will have to replace the outer filter for me...