I'd actually be a little surprised if a large financial services firm doesn't already have malware detection tools installed.  Whether it's one or more of the many endpoint tools (AV, EDR, XDR, pick your acronym) or something on the network looking for behaviors, it's hard…

From your ask, you may need to go with a combination of solutions to provide a best-in-breed defense.  For example, the vendor offering the best EDR/XDR capability for an on-premises deployment may not be the one who provides the best endpoint anti-malware / anti-ransomware…