Ransomware Recap: Is Redboot Really a Wiper?

The ransomware known as Redboot (detected by Trend Micro as RANSOM_REDBOOT.A) leaves victims little hope of recovery as early analysis shows that, along with file encryption, it also alters the master boot record (MBR) and repartitions the hard drive. Because of its ability to cause irreversible damage, Redboot could be classified as a wiper rather than a ransomware. However, news sources say that the authors have confirmed the ransomware is still being developed and will be released in October.

Redboot is a compiled AutoIT executable that will extract five files (assembler.exe, boot.asm, main.exe, overwrite.exe, and protect.exe) into the directory where the launcher was executed. Using these files, it will overwrite the computer’s current master boot record, scan and encrypt files, and also block system tools (like Task Manager) used to help analyze and stop infection. With no distinct way to restore the MBR or the partition, victims of this ransomware are likely to lose their data.

Locky campaigns ramped up

We observed Locky being pushed alongside FAKEGLOBE in a recent spam campaign, opening up the possibility of a victim being infected with two kinds of ransomware from one source. But a larger spam campaign was also detected targeting millions of users. The campaign uses different kinds of spam mail, some from companies sending invoices and others with more generic senders and unidentified attachments.

Figure 1. A spam email impersonating the Herbalife organization

Figure 2. General spam mail supposedly from a voicemail service

The attacks were scattered across the globe, but according to the Trend Micro Smart Protection Network (SPN), the prime targets were India and Chile. On September 18, a variant of Locky started using .yckol ("locky" reversed) as an extension for encrypted files. Their ransom also went down to .25 Bitcoin (around US$1,000), possibly because of the rising value of BTC.

New ransomware still being developed and updated

Bad guys are updating existing ransomware variants and developing new families. SamSam, a crypto-ransomware that we last saw in July, has a new variant that now appends .myransext2017 to the files it encrypts. The CypherPy ransomware (detected by Trend Micro as RANSOM_CYPHERPY) and BlackMist (detected by Trend Micro as RANSOM_BLACKMIST) are two new families that have been recently spotted. InfinityLock (detected by Trend Micro as RANSOM_INFINITYLOCK) is a new family as well, with a gimmick that shows the hacker supposedly encrypting the victim’s files in “real time”.

Meanwhile, Sapnupuas (detected by Trend Micro as RANSOM_SAPNUPUAS and also called nRansom) is a particularly contentious ransomware that is not after ransom money but asks for nude photos instead. Recently the ransomware developers made even more outlandish demands, asking victims to murder ten people and send them a video.

Ransomware will continue to spread, and developers are expected to keep developing their tools and aim at new targets. To defend against the steady tide of evolving ransomware variants, enterprises and users should stay alert and invest in multilayered security solutions.