Open the attachment in Wireshark:
Port 5555, It's ```Network ADB``` , let's dig deeper.

Generally we want to see the document of ADB protocol, which can be found here:
https://github.com/cstyan/adbDocumentation
You can know that ```WRTE``` means the packet is sent to the client.

> you can also skip this if you directly found this packet, but it may be harder afterwards:

So it's actually something about scrcpy.

Filter out packets sent from the compter:
what does these packets mean?


Search the web and you can find this github issue:
https://github.com/Genymobile/scrcpy/issues/673
says there's no documentation, but you can refer to the source code:
https://github.com/Genymobile/scrcpy/blob/6b3d9e3eab1d9ba4250300eccd04528dbee9023a/app/tests/test_control_msg_serialize.c

```c
static void test_serialize_inject_mouse_event(void) {
struct control_msg msg = {
.type = CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT,
.inject_mouse_event =
{
.action = AMOTION_EVENT_ACTION_DOWN,
.buttons = AMOTION_EVENT_BUTTON_PRIMARY,
.position =
{
.point =
{
.x = 260,
.y = 1026,
},
.screen_size =
{
.width = 1080,
.height = 1920,
},
},
},
};
unsigned char buf[CONTROL_MSG_SERIALIZED_MAX_SIZE];
int size = control_msg_serialize(&msg, buf);
assert(size == 18);
const unsigned char expected[] =
{ CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT,
0x00, // AKEY_EVENT_ACTION_DOWN
0x00,
0x00,
0x00,
0x01, // AMOTION_EVENT_BUTTON_PRIMARY
} 0x00,
0x00, 0x01, 0x04, 0x00, 0x00, 0x04, 0x02, // 260 1026
0x04, 0x38, 0x07, 0x80, // 1080 1920
};
assert(!memcmp(buf, expected, sizeof(expected)));
```
Then export the capture file as json and match patterns like above, extracting the points(X,Y):
(fish script, and "57:52:54:45" is the adb command "WRTE" you got from the documentation)
```fish
for i in (cat /home/leohearts/Desktop/tmp.json |jq .[]._source.layers.tcp | grep 57:52:54:45 | grep -o -E '00:00:..:..:00:00:..:..:04:38:08:e8:ff' | grep -o -E '..:..:' | grep -v "00:00" | grep -v '04:38' | grep -v '08:e8' | sed 's/://g')
bash -c 'echo $((16#'$i'))' >> pixels
end
```
Then use Python to draw it back to an image:
```python
from PIL import Image
def newImg():
img = Image.new('RGB', (2000, 2000))
while True:
try:
x = int(input())
y = int(input())
img.putpixel((x,y), (155,155,55))
except:
break
img.save('sqr.png')
return img

wallpaper = newImg()
wallpaper.show()
```
```cat pixels | python3 image.py```
Then thats the flag.