The ASEC analysis team is using the ASEC automatic analysis system RAPIT to categorize and respond to known malware. This post will list weekly statistics collected from May 10th, 2021 (Monday) to May 16th, 2021 (Sunday).
For the main category, info-stealer ranked top with 71.2%, followed by RAT (Remote Administration Tool) malware with 19.9%, CoinMiner with 3.7%, ransomware with 2.8%, and downloader with 2.0%. Backdoor and banking malware each accounted for 0.2%.
Top 1 – AgentTesla
AgentTesla was ranked first place with 33.1%. It is an info-stealer malware that leaks user information saved in web browsers, e-mails, and FTP clients.
Recently collected samples use the following mail servers and user accounts when leaking the collected information.
- paxz[.]tk (162.215.241[.]145)
- mail.karsanmax[.]com (67.20.76[.]71)
- smtp.tttco[.]eu (208.91.199[.]224)
As most are distributed through spam mails disguised as invoices, shipment documents, and purchase orders, the file names contain such words shown above (Invoice, Shipment, 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.
- New PO Order (2).exe
- incorrect bank accountdetails.exe
- MIP8-CIPL 000 HDEC-6042-772.exe
- MACHINE SPECIFICATION.exe
- Wire Payment Of 35276.70.Pdf.exe
- Request for Quotation-4505527156.pdf.exe
- BILL OF LADING 034A522172 QD5D067113 W0675D.pdf.exe
- PURCHASE ORDER
- Proforma ve çeki listesi ektedir.exe
- Price List.exe
- Product inquiry 00897.exe
Top 2 – Formbook
Formbook is an info-stealer malware ranked in second place with 12.4%.
Like other info-stealer malware, it is mainly distributed through spam mails. The distributed file names are also similar to those of other malware.
- Materialliste für Angebot.exe
As Formbook malware is injected in a normal process that is in the directory of explorer.exe and system32, the malicious behaviors are performed by the normal process. Besides web browser user account information, the malware can steal various information through keylogging, clipboard grabbing, and web browser form grabbing. Below is the list of confirmed C&C server URLs of Formbook.
Top 3 – Lokibot
Lokibot takes third place with 13.0%. It is an info-stealer malware that leaks information about programs such as web browsers, mail clients, and FTP clients.
Being a malware that is distributed through spam mails, it shares similar distributed file names with other malware that are distributed through spam mails.
- HY****I PF.exe
- SA****G gFLNG FEED Update RFQ Documents and Contract specifications.exe
- Pharmapia co.,ltd..exe
- Bioclone Corp..exe
As shown in the below, most Lokibot malware C&C server URLs tend to end in fre.php.
Top 4 – SnakeKeylogger
Taking fourth place with 6.1%, SnakeKeylogger is an info-stealer type malware that leaks information such as user key inputs, system clipboards, and browser account information.
Like AgentTesla, this malware uses mail servers and user accounts when leaking collected information. The following is the accounts used by recently collected samples.
- us2.smtp.mailhostbox[.]com (208.91.199[.]225)
- smtp.top-semi[.]xyz (208.91.198[.]143 )
- smtp.vivaldi[.]net (31.209.137[.]12)
Similar to other info-stealer malware, it is distributed through spam mails disguised as invoices, shipment documents, and purchase orders, so the file names contain such words shown above (Invoice, Shipment, P.O. – Purchase Order).
- Statement of Account April-2021.exe
- New Order_WJO-001 pdf.exe
- Original shipping documents PI SKY0003 SOFABED.exePURCHASE_ORDER-38052429.pdf.exe
Top 5 – NanoCore
NanoCore ranks fifth place with 5.9%. It is a RAT malware developed with .NET. Like njRAT, it can perform various commands given by the attacker such as information leakage including keylogging.
Similar to AgentTesla, Formbook, AveMaria, and Remcos, the NanoCore is packed with .NET packing and distributed through attached files in spam mails. As such, the file names reported are not much different from those of other malware distributed through spam mails.
- Passengers details.pif
- ISO OVERVIEW_1552021.pdf.exe
The following list is the confirmed C&C server domains for NanoCore.