Thank You Peter. Your answer is quite convincing. :) 

Luay, Yasir.. I understand both your comments... I have resorted to MS Word for writing my thesis. It would be difficult for me to invest time in learning Latex. By that time, I would progress significantly with my thesis writing in word.

You are absolutely right. I totally endorse your view. But I would stick to word because my thesis is entirely on qualitative research. Since text is the primary thing that comprises 95% of my thesis, I would be much more faster in word. When I write a quantitative research paper, I would learn Latex and use it for sure. For me now, time is a big opportunity cost. Since my thesis is all textual explanations and narratives, Word is fast for me.

But the case you only need to write text, you even do not have to learn anything special with latex. And you still get better spacing, hyphenation and all that stuff in latex than in word.

Converting a text-only document from word to latex is basically a "no-brainer".

What data are you worried about? The attack must be intentional to get your data. It is just like any other website and storage that you use every day. 

The straight answer is that LaTeX has no built-in data security.

Any or all LaTeX data files (*.tex, *.dvi, *.aux, *.log) could potentially be copied, modified or deleted without permission and without the data security incident being detected.

If there is any requirement to preserve the confidentiality and/or integrity and/or availability of LaTeX data then the security controls need to be implemented around LaTeX data files in whatever computing environments are being used to edit them.

The main security control to protect LaTeX data availability would be regular backups.

The main controls to protect the confidentiality of LaTeX data would be access controls (including network access controls, operating system/file system access controls and physical/procedural access controls covering both the main system and the backups) and encryption (both data at rest encryption and encryption of network traffic e.g. using TLS or a VPN).

The main controls to protect integrity would be encryption (both of data at rest and encryption of network traffic), checksums/digital signatures and well-protected granular security event logs tracking all access to the file system(s) containing the LaTeX data files.

If you are storing your LaTeX files on a server controlled by your University then most of these environmental security controls should be provided by the University's IT department. If you are relying on a third party service provider to deliver the security controls you need then you should look for evidence that they conform to an acceptable security standard (e.g. ISO 27001). 

If you are protecting your own information on your own computer equipment, then I would recommend that you learn more about cyber security, perhaps by taking one of the following free online courses:

https://www.futurelearn.com/courses/introduction-to-cyber-security

https://www.futurelearn.com/courses/cyber-security

https://www.coursera.org/learn/information-security-data

https://www.edx.org/course/introduction-cybersecurity-uwashingtonx-cyb001x

In fairness I should point out that, by default, everything that I have written about LaTeX files needing to be secured through controls around the data processing environment also applies to most other desktop applications.  

If information security is really important (as it can be when working on collaborative projects involving partners from other groups or when handling sensitive/personal/classified data) then it is possible to select and implement Digital Rights Management (DRM) solutions which will use cryptography to restrict access to data files. Most recent versions of Microsoft Office include some support for DRM, although setting DRM up and integrating it into the identity and access management (IAM) arrangements of the institution/company concerned (e.g. typically using MS Active Directory) is typically the responsibility of an IT shared service rather than being something that individual researchers would need to establish for themselves.