We don't do brainstorming here but we can help refining what the problem is and looking at the way to approach coming up with ideas for something like this.
We're talking about visual metaphors that evoke the right kind of associations and that set the right mood, tone and associations.
'Cyber' in the late 90's and early 2000's generally evoked the idea of some kind of mysterious new horizon, abstract, overwhelmingly baffling and highly technical: abstract images of a Tron/Matrix-like brave new world, because the reality is something people don't have a comfortable grasp on yet.
Today, it's a day-to-day concrete thing people do casually and comfortably on the sofa, to stay in touch with friends or buy milk. Pretty much the opposite: it's something familiar people just get on with, not something abstract. It's about convenience and simplicity.
Even the most perfectly modern-styled representation of an overwhelming abstract world of high-tech wizardry will look anachronistic because if that's no longer how the topic is thought of, so it's no longer the right thing to evoke, in any style.
The answer of what is the right thing to evoke that works for your company will depend on your exact target audience, but I'd recommend a starting point of not the abstract notion of some cyber network but from the actual day-to-day things that you're making secure.
I'd start by thinking "What's a typical [equivalent of an end user] and what sort of thing would they be doing that we would make secure?". Then think about how to show them in as natural a setting as possible, getting on effortlessly with whatever it is they'll do, looking confident, secure and in control.
Then think about ways of hinting "This has been made safe and secure, this person is even more in control" that keep the mood of it all being simple, straightforward, effortlessly smooth, day-to-day life.
Google-image-searching synonyms for cyber security that don't use the slightly anachronistic word 'cyber' gives a few (uninspired, but illustrative) examples of this very different mood and set of associations:
From Virgin Money:
From Avast (still rather dated, it feels more mid-2000s despite the device shown not having existed then, but it's a stylistic step in the right direction):
Yeah... there aren't many good examples. Hopefully you can come up with some!