z00m

UMCTF2021 - z00m

• Write-Up Author: bluebear [MOCTF]

• Flag:MOCSCTF{Andr01d_RE_1s_3@sy}

Question:

z00m

app-z00m.zip

Write up

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• Use jadx to reverse apk file
• Review the java code, there are two page, the first page is for input the password, the second page will show the serect
• One way to resolve the challenge

1. Find out the password 'N0n-Gue33@b1e-P@55w0rd' from FirstFragment.java
2. Run the apk on Android Emulator, input the password on APP interface.
3. Get the base64 serect.

• Another way to resolve the challenge

1. Find the serect form Strings.xml directly.

• After decoded, you will get the flag MOCSCTF{Andr01d_RE_1s_3@sy}