Rewterz Threat Alert – Zebrocy Infects Targets with Backdoor hosted on Dropbox

Severity

Medium

Analysis Summary

Zebrocy APT operators recently launched campaign using a backdoor to maintain access to victim hosts and extract profiling information. The operators used a Golang-based version instead of the variant written in Delphi. Zebrocy is a toolkit of downloaders, droppers, and backdoors, that is associated with the Russian-speaking advanced threat group Sednit. The hackers are also known by the names APT28, Fancy Bear, Sofacy, Group 74, and STRONTIUM. The group targets governments, embassies and Ministries of Foreign Affairs in Eastern European and Central Asian countries. The document attached to the spear-phishing message is blank but includes a reference to a remote payload. Dropbox is used to host the malicious template – wordData.dotm – containing malicious macros that are executed upon opening the empty document.

Depending on the Microsoft Word version, the VBA macros are disabled by default and user action is required to enable them. It also contains an embedded ZIP archive that the macros dropped and extracted.

Impact

Theft of Sensitive Information

Indicators of Compromise

IP(s) / Hostname(s)

185[.]221[.]202[.]35

URLs

• hxxp[:]//185[.]221[.]202[.]35/software-protection/app[.]php
• hxxps[:]//www[.]dropbox[.]com/s/foughx315flj51u/wordData[.]dotm?dl=1

Filename

• lmss.exe
• ospsvc.dll

Malware Hash (MD5/SHA1/SH256)

• 5C366EF31C5036D3A4AA0BAECFFCEC5EC89106CC5B94989C192877721676105A
• 1d09f491777cc9b80d5e07880314c7b3
• 3652C16479540AFE3E4DA18E32E93F91A9357E81F170296AF99BDABBF527AFB2
• 4c9d9d17702e4ef4898b85e2d41ce8ab
• 2B657E2926D52A9550ECE4590075DCF3CC2BCDCB331BEC9B66F6EE85D2A1214E
• d7f174cd44686c3afc4a9a5ac646f0db
• cd7660ddb2a022a89312965bf29d81c8dd3d5585d8858e626ccac945942c4b4c
• c28d031b3131d62f2a03b037a4ce5199
• 82120b08d8a6342f14243b84ffb0cbe8298fa7ef118897206b3fe3e07cf7005c
• e26fe7f009adb74033be0a18b2847fcc

Remediation

• Block the threat indicators at their respective controls.
• Do not download email attachments coming from untrusted sources.
• Do not enable macros for files unless extremely necessary.