Type
File Name
Location
Sigma was first discovered in November 2017 in enterprise cloud environments.
Name
Sigma
First Seen
November 2017
Sigma is known to target specific file types. Below are all known file types that Sigma is known to infect.
In some cases, ransomware will update the modified date, when it encrypts files. Sigma unknown 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 Sigma ransomware is known to change.
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 Sigma.
Type File Name Location file ReadMe.txt
These are the names of the executables that contain the undetonated ransomware payload for Sigma.
Executables
Sigma.exe, Automated Universal MultiBoot UFD Creation Tool.exe, svchost.exe, svchost (2).exe, GUID.exe.bin, GUID.exe, Marquis Resume.doc, Teofila Resume.doc, Temple Resume.doc, Regina Resume.doc, Garey Resume.doc, Elwyn Resume.doc, Belinda Resume.doc, myfile.exe, taskwgr.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 Sigma.
External Pages
