QBot Trojan delivered via malspam campaign exploiting US election uncertainties

This blog post was authored by Jérôme Segura and Hossein Jazi.

The 2020 US elections have been the subject of intense scrutiny and emotions, while happening in the middle of a global pandemic. As election night ended and uncertainty regarding the results began to creep in, threat actors decided to jump in on it too.

Those tracking the threat landscape know very well that major world events do not go unnoticed by criminals. In this case, we began observing a new spam campaign delivering malicious attachments that exploit doubts about the election process.

The QBot banking Trojan operators return with yet another themed spam wave using the same hijacked email thread technique enticing victims with malicious election interference attachments.

Hijacked email threads pushing bogus DocuSign documents

The malicious emails come as thread replies, similar to what Emotet does to add legitimacy and make detection harder. They contain zip attachments aptly named ElectionInterference_[8 to 9 digits].zip.

While the election results are still being evaluated and debated, victims are enticed to open up the document to read about alleged election interference:

Figure 1: Malicious email with ElectionInterference attachment

The extracted file is an Excel spreadsheet that has been crafted as if it were a secure DocuSign file. Users are tricked to allow macros in order to ‘decrypt’ the document.

Figure 2: Excel document containing malicious macro

This tried and tested trick will download a malicious payload onto the victim’s machine. The URL for that payload is encoded in a cell of a Cyrillic-named sheet “Лист3”.

Figure 3: Payload URL obfuscation

Once executed, the QBot Trojan will contact its command and control server and request instructions. In addition to stealing and exfiltrating data from its victims, QBot will also start grabbing emails that will later be used as part of the next malspam campaigns.

Figure 4: QBot process flow execution

World events are the best lure

At the core of the malware attacks we witness each day are typical social engineering schemes. Threat actors need to get victims to perform a certain set of actions in order to compromise them.

Spam campaigns routinely abuse email delivery notifications (Fedex, DHL, etc.) or bank alerts to disguise malicious payloads. But world events such as the Covid pandemic or the US elections provide ideal material to craft effective schemes resulting in high infection ratios.

Malwarebytes users were already protected against this attack thanks to our Anti-Exploit technology. Additionally, we detect the payload as Backdoor.Qbot.

Figure 5: Malwarebytes blocking the macro from delivering its payload

Indicators of Compromise

Malicious Excel documents

b500a3c769e22535dfc0c0f2383b7b4fbb5eb52097f001814d8219ecbb3048a1
f2fb3e7d69bf1b8c0c20484e94b20be33723b4715e7cf94c5cbb120b800328da
0282a796dec675f556a0bf888eda0fe84f63558afc96321709a298d7a0a4f8e5
e800b0d95e02e6e46a05433a9531d7fb900a45af7999a262c3c147ac23cd4c10
7dec31d782ab776bcbb51bd64cbbd40039805ad94733d644a23d5cf16f85552c
0bec208127e4a021dccb499131ea91062386126b75d098947134a37e41c4b035
30de8dcd4e894549d6d16edb181dd1a7abec8f001c478cf73baf6075756dc8c2
a8329913c8bbccb86b207e5a851f7696b1e8a120929ca5c0a5709bd779babedf
ef8a17c3bb01d58bfea74a19f6cb8573cfb2d94d9e6159709ac15a7e0860dbce
7ddc225ad0ed91ce90b3bde296c5ce0b4649447fb3f02188e5303e22dc7cb5f0

QBot

china[.]asiaspain[.]com/tertgev/1247015.png

1edfe375fafa1f941dc4ee30702f4af31ba636e4b639bcbb90a1d793b5d4b06c
06be75b2f3207de93389e090afd899f392da2e0f1c6e02226db65c61f291b81b

QBot C2s

142.129.227[.]86
95.77.144[.]238

MITRE ATT&CK techniques

Tactic ID Name Details
Execution T1059 Command-Line Interface Starts CMD.EXE for commands execution
T1106 Execution through API Application launched itself
T1053 Scheduled Task Loads the Task Scheduler COM API
Persistence T1050 New Service Executed as Windows Service
T1060 Registry Run Keys / Startup Folder Changes the autorun value in the registry
T1053 Scheduled Task Loads the Task Scheduler COM API
Privilege Escalation T1050 New Service Executed as Windows Service
T1055 Process Injection Application was injected by another process
T1053 Scheduled Task Loads the Task Scheduler COM API
Defense Evasion T1553 Install Root Certificate Changes settings of System certificates
T1055 Process Injection Application was injected by another process
Discovery T1087 Account Discovery Starts NET.EXE to view/change users group
T1135 Network Share Discovery Starts NET.EXE for network exploration
T1069 Permission Groups Discovery Starts NET.EXE to view/change users group
T1012 Query Registry Reads the machine GUID from the registry
T1018 Remote System Discovery Starts NET.EXE for network exploration
T1082 System Information Discovery Reads the machine GUID from the registry
T1016 System Network Configuration Discovery Uses IPCONFIG.EXE to discover IP address