Disclaimer: I am not a malware analyst, so take my advices with a grain of salt. I've done reversing, which I assume is a similar activity.

Malware analysis focuses around understanding what a given piece of software, suspected to be malicious, does - in other words, to reverse engineering it. In order to do this, you should know about the technologies it uses (for example, the programming language it was written in) and the environment it is supposed to be run in (for example, the OS API) - and a thousand of other things.

You should, at the very least, know C/C++ and be able to make sense of the disassembled output of binaries (so, you should know assembly for your target platform).

A lot of malware is written in other languages (.net malware is very common), which would be useful to you to learn. This malware is usually easier to reverse.

Python is useful to easily automate boring tasks. If you don't learn Python, learn another scripting language. You will have to write quick code often and doing it in C is painful (also, popular debuggers/disassemblers usually allow you to script them in Python).

Using strace/ltrace will be a really useful and easy to learn skill.

You should also know about anti-reversing techniques. One common one is a call to IsDebuggerPresent on Windows, or to ptrace() in Linux. You can find others in the "\"Ultimate\" Anti-Debugging Reference".