The NSA has printed a information about learn how to mitigate in opposition to assaults involving the BlackLotus bootkit malware, amid fears that system directors is probably not adequately protected in opposition to the menace.
The BlackLotus UEFI bootkit made a reputation for itself in October 2022, when it was seen being bought on cybercrime underground boards for $5,000.
The information despatched a shiver down the spines of many within the cybersecurity neighborhood, as BlackLotus was the primary in-the-wild UEFI bootkit able to bypassing UEFI Safe Boot on totally up to date UEFI techniques.
BlackLotus is a complicated piece of malware that may infect a pc’s low-level firmware, bypassing the Safe Boot defences constructed into Home windows 10 and Home windows 11, and permitting the execution of malicious code earlier than a PC’s working system and safety defences have loaded.
On this method, attackers may disable safety measures corresponding to BitLocker and Home windows Defender, with out triggering alarms, and deploy BlackLotus’s built-in safety in opposition to the bootkit’s personal elimination.
Though Microsoft issued a patch for the flaw in Safe Boot again in January 2022, its exploitation stays doable because the affected, validly-signed binaries haven’t been added to the UEFI revocation record.
Earlier this 12 months, safety researchers defined how BlackLotus was benefiting from this, “bringing its personal copies of reliable – however weak – binaries to the system as a way to exploit the vulnerability.”
In response to the NSA, there may be “important confusion” in regards to the menace posed by BlackLotus:
“Some organizations use phrases like ‘unstoppable,’ ‘unkillable,’ and ‘unpatchable’ to explain the menace. Different organizations imagine there isn’t any menace as a result of patches that Microsoft launched in January 2022 and early 2023 for supported variations of Home windows. The danger exists someplace between each extremes.”
In response to the NSA’s advisory, patching Home windows 10 and Home windows 11 in opposition to the vulnerabilities is just ” first step.”
In its mitigation information, the company particulars extra steps for hardening techniques.
Nevertheless, as they contain adjustments to how UEFI Safe Boot is configured they need to be undertaken with warning – as they can’t be reversed as soon as activated, and will go away present Home windows boot media unusable if errors are made.
“Defending techniques in opposition to BlackLotus just isn’t a easy repair,” mentioned NSA platform safety analyst Zachary Blum.
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