Hikvision maintains a legacy FTP. Use this carefully:
The demand for legacy Hikvision firmware has led to dangerous third-party sites offering “premium” or “unlocked” firmware. Avoid at all costs: hikvision dvr ds7104hwish firmware download extra quality
Older firmware might cause the DVR to freeze weekly. Premium firmware builds (usually the final releases for this model) provide: Hikvision maintains a legacy FTP