The ZombieLoad attack resurrects your private browsing-history and other sensitive data. It allows to leak information from other applications, the operating system, virtual machines in the cloud and trusted execution environments.
The RIDL attack allows to leak information across various security domains from different buffers, such as line-fill buffers and load ports, inside Intel processors. RIDL demonstrates attacks on other applications, the operating system, other virtual machines and trusted execution environments.
Store-To-Leak Forwarding exploits CPU optimizations introduced by the store buffer to break address randomization, monitor the operating system or to leak data when combined with Spectre gadgets.
Already in March 2018, it was shown by researchers from Graz University of Technology that an attacker can leak data using Meltdown that is not stored in the L1 cache but in one of the line fill buffers. This proof-of-concept, already described in the Meltdown paper, served as the foundation for subsequent research of these buffers. Now these buffers have been exploited with ZombieLoad and RIDL.
Most certainly, yes.
No. These are bugs in the processor. Software can work around these bugs, which costs performance. Future processors will have integrated fixes.
We do not have any data on this. The exploitation might not leave any traces in traditional log files.
While possible in theory, this is unlikely in practice. These attacks are hard to distinguish from regular benign applications. However, your antivirus may detect malware which uses the attacks by comparing binaries after they become known.
We don't know