topic Re: Regex in Splunk Enterprise

How do I create a Regex that doesn't contain random numbers or timestamps?

Kk — Wed, 01 Jun 2022 15:25:11 GMT

Hi All, I'm trying to find the credit card details in the logs with all in one regex expression. But I was also getting some other data too like timestamp data as it has more than 12digits and some random data. Just bit exhausted with this thing here. Is there any possible solution to find the credit card numbers directly that will not contains random numbers or time stamps. Help me with the query if possible.

Thanks in advance.

Re: Regex

ITWhisperer — Wed, 01 Jun 2022 07:11:33 GMT

With regex, it helps to identify some sort of anchor pattern e.g. "card=xxxx". If you don't have this, and you just want to look for strings of 16 digits for example

| rex "\D(?<possiblecard>\d{16})\D"

Re: Regex

Kk — Wed, 01 Jun 2022 08:02:16 GMT

Hi @ITWhisperer , actually we are having many anchor patterns to recognise the card details. Example like card>xxxx, text:xxx. So is their any way to find by using generic query?

Re: Regex

venky1544 — Wed, 01 Jun 2022 08:16:24 GMT

Hi @Kk

Better solution/suggestions can be provided if you paste some sample/dummy data

Re: Regex

ITWhisperer — Wed, 01 Jun 2022 08:18:42 GMT

Regex works with patterns - if you can define what you mean by generic as a pattern, then you might be able to do it in regex. For example, the "generic" pattern is my example is non-digit followed by 16 digits followed by another non-digit. If you know all the anchors you are expecting, you might be able to combine them into a single rex

| rex "(anchor1|anchor2|anchor3)(?<card>\d{16})\D"

Re: Regex

Kk — Wed, 01 Jun 2022 08:50:49 GMT

Yeah we can do in that way but in anchor tag we can't expect only card details. We have some other data too.

Example:

card>xxxxxxxxxx9787<card

card> this is so and so info xxxxxxxx9797<card.

So how can we search card details in these cases.

Re: Regex

ITWhisperer — Wed, 01 Jun 2022 08:56:54 GMT

https://regex101.com/r/eqLFaV/1

| rex "card>.*?\D?(?<card>\d{16})\<card"