Zebrocy

Multiple entries describe APT28/Pawn Storm/Sofacy campaigns using lure documents, themed emails, and phishing schemes, e.g., “APT28 Hacker Group Targeting Europe, Americas, Asia in Widespread Phishing Scheme”, “New Spear Phishing Campaign Pretends to be EFF”, and “distribution of emails with 'instructions' on 'updating the operating system'”.

Examples include “PowerPoint mouse-over event abused to deliver Graphite implants”, “BREXIT-themed lure document that delivers ZEKAPAB malware”, “fake NATO training docs to breach govt networks”, and repeated references to lure documents delivering Zebrocy or Seduploader.

The attack flow, described below, begins with a phishing email containing a malicious shortened URL.

The Golang backdoor can create a pre-defined scheduled task.

The content repeatedly describes malware and threat actors creating, modifying, or invoking Windows scheduled tasks via Task Scheduler or schtasks for persistence, execution, and lateral movement.

The Golang backdoor uses cmd.exe to execute commands.

The content repeatedly describes threat actors and malware using cmd.exe, the Windows command shell, to execute commands, launch payloads, run batch files, and automate actions on compromised hosts.

The file ... with the name “Seminar.rtf” exploited CVE-2017-0199 ... “Seminar.rtf” downloaded a second stage document ... (4de5adb865b5198b4f2593ad436fceff, exploiting CVE-2017-11882) ... we detected a spearphishing GreyEnergy document ... exploiting CVE-2017-11882

Zebrocy attempts to get users to click on Microsoft Office attachments containing malicious macro scripts.

The Golang backdoor can create a pre-defined scheduled task.

The content repeatedly describes malware and threat actors creating, modifying, or invoking Windows scheduled tasks via Task Scheduler or schtasks for persistence, execution, and lateral movement.

ADVSTORESHELL achieves persistence by adding itself to the HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run Registry key... APT28 has deployed malware that has copied itself to the startup directory for persistence... FIN7 malware has created Registry Run and RunOnce keys to establish persistence, and has also added items to the Startup folder.

The Golang backdoor can create a pre-defined scheduled task.

The content repeatedly describes malware and threat actors creating, modifying, or invoking Windows scheduled tasks via Task Scheduler or schtasks for persistence, execution, and lateral movement.

One listed item explicitly names “T1055 Process Injection” and includes APT28-linked malware such as Downdelph among examples.

ADVSTORESHELL achieves persistence by adding itself to the HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run Registry key... APT28 has deployed malware that has copied itself to the startup directory for persistence... FIN7 malware has created Registry Run and RunOnce keys to establish persistence, and has also added items to the Startup folder.

One listed item explicitly names “T1055 Process Injection” and includes APT28-linked malware such as Downdelph among examples.

The content repeatedly describes malware and threat actors deleting files, directories, droppers, logs, scripts, temporary files, exfiltrated archives, and uninstalling themselves to cover tracks or reduce forensic artifacts.

The content is a long ATT&CK-style listing of malware and threat groups that 'decrypt', 'decode', 'deobfuscate', 'unpack', or 'decompress' payloads, strings, configuration data, shellcode, and files prior to execution or use.

The packed executable loads an AutoIt payload into memory.

Agent Tesla can gather credentials from a number of browsers... APT33 has used a variety of publicly available tools like LaZagne to gather credentials... TrickBot can obtain passwords stored in files from web browsers such as Chrome, Firefox, Internet Explorer, and Microsoft Edge... SELECT action_url, username_value, password_value FROM logins; CryptUnprotectData

Agent Tesla can gather credentials from a number of browsers... APT3 has used tools to dump passwords from browsers... APT41 used BrowserGhost, a tool designed to obtain credentials from browsers, to retrieve information from password stores... TrickBot can obtain passwords stored in files from web browsers such as Chrome, Firefox, Internet Explorer, and Microsoft Edge

AdFind can extract subnet information from Active Directory; actors used ipconfig /all, netsh.exe, ifconfig, arp, route, nbtstat, and related APIs/commands to gather IP, MAC, DNS, DHCP, gateway, proxy, routing, ARP, and adapter information.

The content repeatedly describes malware and threat actors collecting the victim username, identifying logged-in users, running whoami, query user, quser, or similar commands to determine the current user or user sessions.

Tasklist can be used to discover processes running on a system. Numerous malware families and threat groups are described as listing running processes, collecting PIDs, checking for specific process names, or enumerating loaded modules.

The content repeatedly describes malware and threat actors collecting OS version, computer name, architecture, CPU, memory, disk, language, and other host details; examples include use of commands such as ver, systeminfo, hostname, uname -m, sw_vers -productVersion, and fsutil.

The content is a long ATT&CK-style listing of groups and malware that can 'list files and directories,' 'search for files,' 'enumerate drives,' 'gather file metadata,' or 'browse file systems' on compromised hosts.

Numerous entries mention enumerating drives, logical disks, disk type, free space, or volume information; examples include 'Babuk can enumerate disk volumes,' 'Cuba can enumerate local drives,' and 'TAINTEDSCRIBE can use DriveList to retrieve drive information.'

The content repeatedly describes malware and threat actors collecting the current date, time, or time zone from victim systems, including examples such as "The net time command can be used... to determine the local or remote system time" and commands like "net time \\hostname" and "w32tm /tz".

APT1 listed connected network shares. APT32 used the net view command to show all shares available, including the administrative shares such as C$ and ADMIN$. APT41 used the net share command as part of network reconnaissance.

The content is a MITRE ATT&CK-style listing of malware and threat actors that "can capture screenshots," "take screenshots," "perform screen captures," or "watch the victim's screen." It ends with references to "CopyFromScreen" and "xwd."

Both sets of activity used the same servers at the same time and targeted the same organization... different Zebrocy C2 servers, including 193.23.181[.]151 ... Another server we detected that was used both by Zebrocy and by GreyEnergy is 185.217.0[.]124 ... They retrieve additional data from the following URL...

The content is a long ATT&CK-style listing showing numerous malware families and threat groups that 'use HTTP,' 'use HTTPS,' 'HTTP POST requests,' 'HTTP GET requests,' or 'HTTP/S' for command and control communications.

The content repeatedly describes malware and threat actors that can "download files from C2," "download additional payloads," "upload and download files," "retrieve payloads from the C2 server," and "copy files to remote machines."

ADVSTORESHELL C2 traffic is encrypted, then encoded with Base64 encoding. APT19 HTTP malware variant used Base64 to encode communications to the C2 server. APT33 has used base64 to encode command and control traffic.

Cobalt Strike can use Base64, URL-safe Base64, or NetBIOS encoding in its C2 traffic. More_eggs has used basE91 encoding, along with encryption, for C2 communication. Zebrocy has used URL/Percent Encoding on data exfiltrated via HTTP POST requests.

ADVSTORESHELL exfiltrates data over the same channel used for C2.