Type
File Name
Location
Jeffery was first discovered in April 2025 in enterprise cloud environments.
Name
Jeffery
First Seen
April 2025
Jeffery is known to target specific file types. Below are all known file types that Jeffery is known to infect.
In some cases, ransomware will update the modified date, when it encrypts files. Jeffery updates the last modified date of the file it targets.
Some ransomware will change or append a suffix to the end of the file after they are encrypted, including changing the extension of a file. Here are some of the possible suffixes that Jeffery ransomware is known to change.
Suffixes
.Jeffery
Not all ransomware leaves a note. However, some ransomware leaves the infected party instructions on what the user should do to get rid of the ransomware, or satisfy the ransom. This often involves transferring money, often bitcoin or another cryptocurrency to a designated wallet.
Below are the type(s) of notes, content, and typical locations where Elastio has found ransom notes from Jeffery.
Type File Name Location file JEFFERY_README.txt Desktop screenshot Desktop
These are the names of the executables that contain the undetonated ransomware payload for Jeffery.
Executables
School Homework.exe
Ransomware often links to external pages such as payment pages, telegram contacts, etc. Below are some of the URLs Elastio has found to be associated with Jeffery.
External Pages
