This indicates an attack attempt against a File Access vulnerability in ImageMagick.
The vulnerability is caused by improper validation of image files. A remote attacker may be able to exploit this to move arbitrary file on the affected system, via a crafted file.
ImageMagick 6.x before 6.9.3-10
ImageMagick 7.x before 7.0.1-1
Security Bypass: Remote attackers can bypass security checks of vulnerable systems to move arbitrary files.
Apply the most recent upgrade or patch from the vendor.