Possible malware through Lightning to HDMI adapter?

[no0nefamous]

My friend bought some random no-name Chinese Lightning to HDMI adapter off of Amazon. Without thinking, I was the first one to test it out with my phone to connect it to a TV. I was startled because at first the adapter displayed an amateur "Welcome" splash page with Chinese text on it on the TV. It did eventually mirror the phone screen correctly, but I thought it was just adapter and shouldn't have the ability to even display a splash page on the TV.

Also, the reviews for the listing are questionable as most seem to be for some sort of charging cable:

[Apple MFi Certified] Lightning to HDMI Digital Adapter, 5 FT Cable Compatible with iPhone, iPad, iPod 1080P AV Sync Screen Connector on HDTV Monitor Projector-NO Need Power Supply

[Apple MFi Certified] Lightning to HDMI Digital Adapter, 5 FT Cable Compatible with iPhone, iPad, iPod 1080P AV Sync Screen Connector on HDTV Monitor Projector-NO Need Power Supply

www.amazon.com

Well, I know this is probably paranoid sounding, but is there any way that this could have installed malware on my phone? If so, how can I check? I might just do a restore process just to be safe.

 

[Reno Raines]

I could be wrong but I have never heard of a cable giving a phone malware.

 

[no0nefamous]

I could be wrong but I have never heard of a cable giving a phone malware.

I know it sounds silly. It's just an adapter cable, right? But why was it able to display some sort of splash image on the TV before mirroring the phone screen? That's what I don't understand and why it's a little concerning.

 

[arw]

I know it sounds silly. It's just an adapter cable, right? But why was it able to display some sort of splash image on the TV before mirroring the phone screen? That's what I don't understand and why it's a little concerning.

Don‘t worry. I had the same happening with a cheap Lightning > HDMI adapter. Mirror/video quality was also nowhere near of what I was expecting. The HDMI adapter runs a separate small OS and this is where the splash logo / animation is from. IIRC all cheap cables use some sort of lossy Airplay for video/audio transmission and the HDMI plug runs a software to act as a receiver. Plugging the cable into the phone simply initiates the pairing but it is not using the Lightning connector to properly transfer the data.

I found only the original Apple adapter to losslessly play (up to 1080p) videos via HDMI (including dolby digital 5.1 sound). Also mirroring is of vastly superior quality.
Apparently it runs its own version of iOS with an ARM SoC that directly communicates with the phone.
This is why the adapter gets so hot, is so expensive but can deliver 1080p video through Lightning.

(btw I got a refund on the cheap one and trashed it)

 

[no0nefamous]

Don‘t worry. I had the same happening with a cheap Lightning > HDMI adapter. Mirror/video quality was also nowhere near of what I was expecting. The HDMI adapter runs a separate small OS and this is where the splash logo / animation is from. IIRC all cheap cables use some sort of lossy Airplay for video/audio transmission and the HDMI plug runs a software to act as a receiver. Plugging the cable into the phone simply initiates the pairing but it is not using the Lightning connector to properly transfer the data.

I found only the original Apple adapter to losslessly play (up to 1080p) videos via HDMI (including dolby digital 5.1 sound). Also mirroring is of vastly superior quality.
Apparently it runs its own version of iOS with an ARM SoC that directly communicates with the phone.
This is why the adapter gets so hot, is so expensive but can deliver 1080p video through Lightning.

(btw I got a refund on the cheap one and trashed it)

Thanks for the response. That makes sense. I assumed it was literally just an adapter cable and didn't know extra processing was going on.

Would the same thing be true for USB-C to HDMI adapters? I have one that I use for my iMac and laptop that works perfectly. Or is that different because the iMac and laptop inherently can transmit video through HDMI?

 

[arw]

Would the same thing be true for USB-C to HDMI adapters? I have one that I use for my iMac and laptop that works perfectly. Or is that different because the iMac and laptop inherently can transmit video through HDMI?

For Macs /PCs I have never heard of anything familiar. They (should) strictly follow the protocols of Displayport / HDMI.

(Just to explain why I didn't mention USB: USB type C is just describing the connector and does not directly specify which functions (data/video/charging) they support in detail. If USB-C works for video, it's using the DisplayPort-Alt mode or HDMI alt mode. But that's not directly relevant for your question.)

EDIT: For the sake of completeness, there is DisplayLink. But devices using this technology are mostly clearly labeled as it‘s a feature worth advertising. This technology simulates a virtual graphics card via software so that a designated USB adapter/dock/cable can output a video signal via HDMI/Displayport. This is useful a.e. for M1 MacBooks/iMacs that by design only support one external display. DisplayLink lets you connect additional displays.