Online multiplayer functionality has been restored for Dark Souls II and Dark Souls III after a 2-week blackout. Co-op and PVP activities were unavailable for the affected two weeks. Players who were unable to enjoy the co-op multiplayer and PVP were finally able to get back into action. This marks an important fix to a major issue affecting the community for both Dark Souls II and III.
Co-op and PvP modes return after two-week security blackout
FromSoftware at the outset suspended all servers for these games across all platforms. FromSoft justified the server shutdown as an emergency due to detected security vulnerabilities. The temporary server suspension was put in place in order to protect players data and the stability of the network while the investigation was ongoing.
The server suspension lasted around 14 days (starting late October). FromSoft published a statement apologizing for the inconvenience and thanked players for their patience. FromSoftware stated that the investigation is completed and the problem is fully fixed.
FromSoft didn't reveal the technical details of the security flaws. We don't know the details about the vulnerabilities. Technical details of the vulnerabilities were not revealed but the main goal was to get the online services stable again.
Source: IXBT
Two weeks offline for a bug nobody explained. Standard FromSoft move.