Apk-medit is a memory search and patch tool for debuggable apk without root & ndk. It was created for mobile game security testing.
This is a demo that uses apk-medit to clear a game that requires one million taps to clear.
Download the binary from GitHub Releases, please push the binary in /data/local/tmp/
on an android device.
$ adb push medit /data/local/tmp/medit
medit: 1 file pushed. 29.0 MB/s (3135769 bytes in 0.103s)
You can build with make command. It requires a go compiler.
After the build is complete, if adb is connected, it pushes the built binary in /data/local/tmp/
on an android device.
$ make
GOOS=linux GOARCH=arm64 GOARM=7 go build -o medit
/bin/sh -c "adb push medit /data/local/tmp/medit"
medit: 1 file pushed. 23.7 MB/s (3131205 bytes in 0.126s)
Use the run-as
command to read files used by the target app, so apk-medit can only be used with apps that have the debuggable attribute enabled.
To enable the debuggable attribute, open AndroidManifest.xml
, add the following xml attribute in application xml node:
android:debuggable="true"
After running the run-as
command, directory is automatically changed. So copy medit
from /data/local/tmp/
.
Running medit
launches an interactive prompt.
$ adb shell
$ pm list packages # to check <target-package-name>
$ run-as <target-package-name>
$ cp /data/local/tmp/medit ./medit
$ ./medit
Here are the commands available in an interactive prompt.
Search the specified integer on memory.
> find 999982
Search UTF-8 String...
Target Value: 999982([57 57 57 57 56 50])
Found: 0!
------------------------
Search Word...
parsing 999982: value out of range
------------------------
Search Double Word...
Target Value: 999982([46 66 15 0])
Found: 1!
Address: 0xe7021f70
You can also specify datatype such as string, word, dword, qword.
> find dword 999996
Search Double Word...
Target Value: 999996([60 66 15 0])
Found: 1!
Address: 0xe7021f70
Filter previous search results that match the current search results.
> filter 993881
Check previous results of searching dword...
Target Value: 993881([89 42 15 0])
Found: 1!
Address: 0xe7021f70
Write the specified value on the address found by search.
> patch 10
Successfully patched!
Find the target process and if there is only one, specify it as the target. ps
runs automatically on startup.
> ps
Package: jp.aktsk.tap1000000, PID: 4398
Target PID has been set to 4398.
If target pid set by ps
, attach to the target process, stop all processes in the app by ptrace.
> attach
Target PID: 4398
Attached TID: 4398
Attached TID: 4405
Attached TID: 4407
Attached TID: 4408
Attached TID: 4410
Attached TID: 4411
Attached TID: 4412
Attached TID: 4413
Attached TID: 4414
Attached TID: 4415
Attached TID: 4418
Attached TID: 4420
Attached TID: 4424
Attached TID: 4429
Attached TID: 4430
Attached TID: 4436
Attached TID: 4437
Attached TID: 4438
Attached TID: 4439
Attached TID: 4440
Attached TID: 4441
Attached TID: 4442
If target pid is not set, it can be specified on the command line.
> attach <pid>
Detach from the attached process.
> detach
Detached TID: 4398
Detached TID: 4405
Detached TID: 4407
Detached TID: 4408
Detached TID: 4410
Detached TID: 4411
Detached TID: 4412
Detached TID: 4413
Detached TID: 4414
Detached TID: 4415
Detached TID: 4418
Detached TID: 4420
Detached TID: 4424
Detached TID: 4429
Detached TID: 4430
Detached TID: 4436
Detached TID: 4437
Detached TID: 4438
Detached TID: 4439
Detached TID: 4440
Detached TID: 4441
Detached TID: 4442
Display memory dump like hexdump.
> dump 0xf0aee000 0xf0aee300
Address range: 0xf0aee000 - 0xf0aee300
----------------------------------------------
00000000 34 32 20 61 6e 73 77 65 72 20 28 74 6f 20 6c 69 |42 answer (to li|
00000010 66 65 20 74 68 65 20 75 6e 69 76 65 72 73 65 20 |fe the universe |
00000020 65 74 63 7c 33 29 0a 33 31 34 20 70 69 0a 31 30 |etc|3).314 pi.10|
00000030 30 33 20 61 75 64 69 74 64 20 28 61 76 63 7c 33 |03 auditd (avc|3|
00000040 29 0a 31 30 30 34 20 63 68 61 74 74 79 20 28 64 |).1004 chatty (d|
00000050 72 6f 70 70 65 64 7c 33 29 0a 31 30 30 35 20 74 |ropped|3).1005 t|
00000060 61 67 5f 64 65 66 20 28 74 61 67 7c 31 29 2c 28 |ag_def (tag|1),(|
00000070 6e 61 6d 65 7c 33 29 2c 28 66 6f 72 6d 61 74 7c |name|3),(format||
00000080 33 29 0a 31 30 30 36 20 6c 69 62 6c 6f 67 20 28 |3).1006 liblog (|
00000090 64 72 6f 70 70 65 64 7c 31 29 0a 32 37 31 38 20 |dropped|1).2718 |
000000a0 65 0a 32 37 31 39 20 63 6f 6e 66 69 67 75 72 61 |e.2719 configura|
000000b0 74 69 6f 6e 5f 63 68 61 6e 67 65 64 20 28 63 6f |tion_changed (co|
000000c0 6e 66 69 67 20 6d 61 73 6b 7c 31 7c 35 29 0a 32 |nfig mask|1|5).2|
000000d0 37 32 30 20 73 79 6e 63 20 28 69 64 7c 33 29 2c |720 sync (id|3),|
000000e0 28 65 76 65 6e 74 7c 31 7c 35 29 2c 28 73 6f 75 |(event|1|5),(sou|
000000f0 72 63 65 7c 31 7c 35 29 2c 28 61 63 63 6f 75 6e |rce|1|5),(accoun|
To exit medit, use the exit
command or Ctrl-D
.
> exit
Bye!
You can run test codes with make command.
$ make test
MIT License