ASEC (AhnLab Security Emergency response Center) uses the ASEC automatic analysis system RAPIT to categorize and respond to known malware. This post will list weekly statistics collected from February 20th, 2023 (Monday) to February 26th, 2023 (Sunday).
For the main category, backdoor ranked top with 51.0%, followed by downloader with 24.7%, Infostealer with 22.7%, ransomware with 1.4%, and CoinMiner with 0.2%.
Top 1 – RedLine
RedLine ranked first place with 46.9%. The malware steals various information such as web browsers, FTP clients, cryptocurrency wallets, and PC settings. It can also download additional malware by receiving commands from the C&C server. Like BeamWinHTTP, there have been numerous cases of RedLine being distributed under the disguise of a software crack file.
The following are the confirmed C&C server domains for RedLine:
Top 2 – Amadey
This week, Amadey Bot ranked second place with 13.9%. Amadey is a downloader that can receive commands from the attacker to download additional malware, and when info-stealing modules are used, it can collect user credentials in the infected system.
Usually, Amadey is installed by SmokeLoader which is distributed in the disguise of normal programs and crack malware. In the recent days, however, Amadey is being distributed to corporate users through malicious document files attached to spam mails and being used to install LockBit ransomware.
The confirmed C&C server URLs are as follows.
Top 3 – AgentTesla
- SMTP Server : us2.smtp.mailhostbox[.]com
User : email@example.com
Password : ” LC%UjB****nSacr@@ “
Receiver : firstname.lastname@example.org
- SMTP Server : smtp.yandex[.]com
User : email@example.com
Password : Oma****29#
Receiver : firstname.lastname@example.org
- SMTP Server : smtp.yandex[.]com
User : email@example.com
Password : mar****nus360
Recervier : firstname.lastname@example.org
- Telegram API : hxxps://api.telegram[.]org/bot1507062795:AAEBb0H5OYbp-dWwXk8ffQp0InjOhKxhpbU/sendDocument
As most are distributed through spam emails disguised as invoices, shipment documents, and purchase orders, the file names contain such words shown above (Invoice, Shipment, and P.O. – Purchase Order). Multiple collected samples were disguised as files with extensions of pdf and xlsx.
- AWB733988905AA DHL Package 733988905AA.exe
- BL Draft and Shipping Documents.exe
- DHL Scan Docs_xls.exe
- ORDER NUMBER 94043 QUOTATION.exe
- PI 160256.exe
- Scan Document_xls.exe
- Technical DataSheet.exe
Top 4 – BeamWinHTTP (Tied)
BeamWinHTTP is a downloader malware that ranked fourth with 4.9%. The malware is distributed via malware disguised as PUP installer. When it is executed, it installs PUP malware Garbage Cleaner and can download and install additional malware at the same time.
Top 4 – Guloader (Tied)
GuLoader, which ranked fourth place with 4.9%, is a downloader malware that downloads additional malware and runs it. It was packed with Visual Basic language in the past to bypass detection, but it is now distributed in a form of an NSIS installer. It used to be known as CloudEye but got the name GuLoader because Google Drive is frequently used as a download URL. In addition to Google Drive, various URLs such as One Drive from Microsoft can also be used.
Instead of being downloaded in a file form, GuLoader is downloaded on memory to avoid detection, and the downloaded file is encoded, not PE. It is then executed after being decoded in the memory, downloading malware such as Infostealers (Formbook and AgentTesla) and RAT (Remcos and NanoCore).
As most are distributed through spam emails disguised as invoices, shipment documents, and purchase orders, the file names contain such words shown above (Invoice, Shipment, and P.O. – Purchase Order). Some samples have extensions disguised as document files such as pdf and xlsx or Auto CAD blueprint files such as dwg.
- (Facility) 2023.02.23_LG Chem Associate Evaluation_Requested Files.exe
- Anthracoid Overmodernization.exe
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