Armouring reverse_tcp to evade antivirus detection
This was the presentation I held on 23rd March 2019 at the BSides Dublin 2019.
Signature verification bypass vulnerability in some Huawei routers
This blog will describe the discovery of the digital signature bypass on some Huawei routers. The idea of digital signature check is simple - you have a piece of code and you calculated the checksum/hash of that file. The hash or checksum can be thought of as a "signature", a mathematical value that is uniquely assigned to the code (in our case the code was a firmware file). As soon as you change anything in the file and recalculate the hash, it should be significantly different from the original value - that is the feature of the hashing algorithm. Even the small change in the code will change the hash significantly. Vendors in most cases provide the such a pre-calculated hash so that the customer or the system may check if the hash of the image is indeed the same as vendor required. What was found in this investigation was that the system command on the Huawei AR1220E router does not perform this check properly. As a consequence, the attacker might be abl
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