Seriously, in which parallel universe can one "find" wallets with ~332k bitcoins?
Hell, it would be a helluva miracle ngl. But as I stated, I found it uploaded onto an online directory (anyone can find it if they know what to search). I downloaded it to see how stupid they must be to leave a file like that just out there. It shows up to me and most likely everyone else who downloads it as 'corrupted' as we aren't the ones to import those addresses (this sentence is just my assumption as I don't know if that's how it actually works). The person/group of people who foolishly decided to leave the file out in the open most likely have the actual access to these addresses.
Here's my thought, it's fake wallet file designed to waste someone time or scam someone else. Please read post i quote below,
The wallet file isn't fake per se, nor are the transactions it shows. What's fake about it is that it doesn't contain the private keys it claims it does.
The method of identification is to look at the corresponding version of the wallet code, check the data consistency, time, field, type, structure, It looks very complicated.
It actually is not that complicated. You don't need to check any data consistency, time, etc. You don't need to check any of the things you mentioned. You also don't really need to look at the wallet code because the data that they are manipulating doesn't change frequently, if ever. In fact, the specific database fields that are being modified will likely never change in order to maintain backwards compatibility with older wallet versions.
What the authors have done here is simply add fields which represent encrypted keys. These fields contain the pubkey and the encrypted private key which will typically just look like random data (because that's the point of encryption). What the authors have done is just create a field that contains the pubkey and random data (or in this case, a string) as the private key.
It is impossible for anyone (technical or not, professional or not) to identify that the wallet is "fake" by simply looking at it (besides the fact that common sense tells you its a scam). If done correctly, the supposed encrypted key will be garbage data and its veracity cannot be determined without knowing the decryption key. Of course, if it's just zeroes or some other obvious non-random data, then it can be easily determined. You can inspect the data of a wallet.dat file using BDB 4.6's db_dump tool.
While he's talking about fake Bitcoin Core wallet file, the principle should be similar for fake Electrum wallet file.