This indicates an attempt to exploit a buffer-overflow vulnerability in DjVu.
This vulnerability is due to a program error that leads to a buffer overflow in the "DjVu_ActiveX_MSOffice.dll" ActiveX control. The overflow occurs when processing an overly long argument passed to the "ImageURL" property. A remote attacker may exploit this to execute arbitrary code.
Any version of DjVu
Currently we are not aware of any vendor-supplied patch for this issue.