Files
2022-12-13 09:57:25 +01:00

490 lines
16 KiB
Go

package alias
/*
Sliver Implant Framework
Copyright (C) 2019 Bishop Fox
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
import (
"context"
"encoding/json"
"fmt"
"os"
"path"
"path/filepath"
"strings"
"github.com/AlecAivazis/survey/v2"
"github.com/bishopfox/sliver/client/assets"
"github.com/bishopfox/sliver/client/command/help"
"github.com/bishopfox/sliver/client/console"
consts "github.com/bishopfox/sliver/client/constants"
"github.com/bishopfox/sliver/protobuf/clientpb"
"github.com/bishopfox/sliver/protobuf/sliverpb"
"github.com/bishopfox/sliver/util"
"github.com/desertbit/grumble"
"google.golang.org/protobuf/proto"
)
const (
defaultTimeout = 60
ManifestFileName = "alias.json"
windowsDefaultHostProc = `c:\windows\system32\notepad.exe`
linuxDefaultHostProc = "/bin/bash"
macosDefaultHostProc = "/Applications/Safari.app/Contents/MacOS/SafariForWebKitDevelopment"
)
var (
// alias name -> manifest/command
loadedAliases = map[string]*loadedAlias{}
defaultHostProc = map[string]string{
"windows": windowsDefaultHostProc,
"linux": windowsDefaultHostProc,
"darwin": macosDefaultHostProc,
}
)
// Ties the manifest struct to the command struct
type loadedAlias struct {
Manifest *AliasManifest
Command *grumble.Command
}
// AliasFile - An OS/Arch specific file
type AliasFile struct {
OS string `json:"os"`
Arch string `json:"arch"`
Path string `json:"path"`
}
// AliasManifest - The manifest for an alias, contains metadata
type AliasManifest struct {
Name string `json:"name"`
Version string `json:"version"`
CommandName string `json:"command_name"`
OriginalAuthor string `json:"original_author"`
RepoURL string `json:"repo_url"`
Help string `json:"help"`
LongHelp string `json:"long_help"`
Entrypoint string `json:"entrypoint"`
AllowArgs bool `json:"allow_args"`
DefaultArgs string `json:"default_args"`
Files []*AliasFile `json:"files"`
IsReflective bool `json:"is_reflective"`
IsAssembly bool `json:"is_assembly"`
RootPath string `json:"-"`
}
func (ec *AliasManifest) getDefaultProcess(targetOS string) (proc string, err error) {
proc, ok := defaultHostProc[targetOS]
if !ok {
err = fmt.Errorf("no default process for %s target, please specify one", targetOS)
}
return
}
func (a *AliasManifest) getFileForTarget(cmdName string, targetOS string, targetArch string) (string, error) {
filePath := ""
for _, extFile := range a.Files {
if targetOS == extFile.OS && targetArch == extFile.Arch {
filePath = path.Join(assets.GetAliasesDir(), a.CommandName, extFile.Path)
break
}
}
if filePath == "" {
err := fmt.Errorf("no alias file found for %s/%s", targetOS, targetArch)
return "", err
}
if _, err := os.Stat(filePath); os.IsNotExist(err) {
err = fmt.Errorf("alias file not found: %s", filePath)
return "", err
}
return filePath, nil
}
// AliasesLoadCmd - Locally load a alias into the Sliver shell.
func AliasesLoadCmd(ctx *grumble.Context, con *console.SliverConsoleClient) {
dirPath := ctx.Args.String("dir-path")
alias, err := LoadAlias(dirPath, con)
if err != nil {
con.PrintErrorf("Failed to load alias: %s\n", err)
} else {
con.PrintInfof("%s alias has been loaded\n", alias.Name)
}
}
// LoadAlias - Load an alias into the Sliver shell from a given directory
func LoadAlias(manifestPath string, con *console.SliverConsoleClient) (*AliasManifest, error) {
// retrieve alias manifest
var err error
manifestPath, err = filepath.Abs(manifestPath)
if err != nil {
return nil, err
}
// parse it
data, err := os.ReadFile(manifestPath)
if err != nil {
return nil, err
}
aliasManifest, err := ParseAliasManifest(data)
if err != nil {
return nil, err
}
aliasManifest.RootPath = filepath.Dir(manifestPath)
// for each alias command, add a new app command
// do not add if the command already exists
if cmdExists(aliasManifest.CommandName, con.App) {
return nil, fmt.Errorf("'%s' command already exists", aliasManifest.CommandName)
}
helpMsg := fmt.Sprintf("[%s] %s", aliasManifest.Name, aliasManifest.Help)
longHelpMsg := help.FormatHelpTmpl(aliasManifest.LongHelp)
longHelpMsg += "\n\n⚠️ If you're having issues passing arguments to the alias please read:\n"
longHelpMsg += "https://github.com/BishopFox/sliver/wiki/Aliases-&-Extensions#aliases-command-parsing"
addAliasCmd := &grumble.Command{
Name: aliasManifest.CommandName,
Help: helpMsg,
LongHelp: longHelpMsg,
Run: func(extCtx *grumble.Context) error {
con.Println()
runAliasCommand(extCtx, con)
con.Println()
return nil
},
Flags: func(f *grumble.Flags) {
if aliasManifest.IsAssembly {
f.String("m", "method", "", "Optional method (a method is required for a .NET DLL)")
f.String("c", "class", "", "Optional class name (required for .NET DLL)")
f.String("d", "app-domain", "", "AppDomain name to create for .NET assembly. Generated randomly if not set.")
f.String("a", "arch", "x84", "Assembly target architecture: x86, x64, x84 (x86+x64)")
f.Bool("i", "in-process", false, "Run in the current sliver process")
f.String("r", "runtime", "", "Runtime to use for running the assembly (only supported when used with --in-process)")
f.Bool("M", "amsi-bypass", false, "Bypass AMSI on Windows (only supported when used with --in-process)")
f.Bool("E", "etw-bypass", false, "Bypass ETW on Windows (only supported when used with --in-process)")
}
f.String("p", "process", "", "Path to process to host the shared object")
f.String("A", "process-arguments", "", "arguments to pass to the hosting process")
f.Uint("P", "ppid", 0, "parent process ID to use when creating the hosting process (Windows only)")
f.Bool("s", "save", false, "Save output to disk")
f.Int("t", "timeout", defaultTimeout, "command timeout in seconds")
},
Args: func(a *grumble.Args) {
a.StringList("arguments", "arguments", grumble.Default([]string{}))
},
HelpGroup: consts.AliasHelpGroup,
}
con.App.AddCommand(addAliasCmd)
// Have to use a global map here, as passing the aliasCmd
// either by value or by ref fucks things up
loadedAliases[aliasManifest.CommandName] = &loadedAlias{
Manifest: aliasManifest,
Command: addAliasCmd,
}
return aliasManifest, nil
}
// ParseAliasManifest - Parse an alias manifest
func ParseAliasManifest(data []byte) (*AliasManifest, error) {
// parse it
alias := &AliasManifest{}
err := json.Unmarshal(data, alias)
if err != nil {
return nil, err
}
if alias.Name == "" {
return nil, fmt.Errorf("missing alias name in manifest")
}
if alias.CommandName == "" {
return nil, fmt.Errorf("missing command.name in alias manifest")
}
if alias.Help == "" {
return nil, fmt.Errorf("missing command.help in alias manifest")
}
for _, aliasFile := range alias.Files {
if aliasFile.OS == "" {
return nil, fmt.Errorf("missing command.files.os in alias manifest")
}
aliasFile.OS = strings.ToLower(aliasFile.OS)
if aliasFile.Arch == "" {
return nil, fmt.Errorf("missing command.files.arch in alias manifest")
}
aliasFile.Arch = strings.ToLower(aliasFile.Arch)
aliasFile.Path = util.ResolvePath(aliasFile.Path)
if aliasFile.Path == "" || aliasFile.Path == "/" {
return nil, fmt.Errorf("missing command.files.path in alias manifest")
}
}
return alias, nil
}
func runAliasCommand(ctx *grumble.Context, con *console.SliverConsoleClient) {
session, beacon := con.ActiveTarget.GetInteractive()
if session == nil && beacon == nil {
return
}
var goos string
var goarch string
if session != nil {
goos = session.OS
goarch = session.Arch
} else {
goos = beacon.OS
goarch = beacon.Arch
}
loadedAlias, ok := loadedAliases[ctx.Command.Name]
if !ok {
con.PrintErrorf("No alias found for `%s` command\n", ctx.Command.Name)
return
}
aliasManifest := loadedAlias.Manifest
binPath, err := aliasManifest.getFileForTarget(ctx.Command.Name, goos, goarch)
if err != nil {
con.PrintErrorf("Fail to find alias file: %s\n", err)
return
}
args := ctx.Args.StringList("arguments")
var extArgs string
if len(aliasManifest.DefaultArgs) != 0 && len(args) == 0 {
extArgs = aliasManifest.DefaultArgs
} else {
extArgs = strings.Join(args, " ")
}
extArgs = strings.TrimSpace(extArgs)
entryPoint := aliasManifest.Entrypoint
processArgsStr := ctx.Flags.String("process-arguments")
// Special case for payloads with pass to Donut (.NET assemblies and sideloaded payloads):
// The Donut loader has a hard limit of 256 characters for the command line arguments, so
// we're alerting the user that the arguments will be truncated.
if len(extArgs) > 256 && (aliasManifest.IsAssembly || !aliasManifest.IsReflective) {
msgStr := ""
// The --in-process flag only exists for .NET assemblies (aliasManifest.IsAssembly == true).
// Groupping the two conditions together could crash the client since ctx.Flags.Type panics
// if the flag is not registered.
if aliasManifest.IsAssembly {
if !ctx.Flags.Bool("in-process") {
msgStr = " Arguments are limited to 256 characters when using the default fork/exec model for .NET assemblies.\nConsider using the --in-process flag to execute .NET assemblies in-process and work around this limitation.\n"
}
} else if !aliasManifest.IsReflective {
msgStr = " Arguments are limited to 256 characters when using the default fork/exec model for non-reflective PE payloads.\n"
}
con.PrintWarnf(msgStr)
confirm := false
prompt := &survey.Confirm{Message: "Do you want to continue?"}
survey.AskOne(prompt, &confirm, nil)
if !confirm {
return
}
}
processArgs := strings.Split(processArgsStr, " ")
processName := ctx.Flags.String("process")
if processName == "" {
processName, err = aliasManifest.getDefaultProcess(goos)
if err != nil {
con.PrintErrorf("%s\n", err)
return
}
}
isDLL := false
if strings.ToLower(filepath.Ext(binPath)) == ".dll" {
isDLL = true
}
binData, err := os.ReadFile(binPath)
if err != nil {
con.PrintErrorf("%s\n", err)
return
}
var outFilePath *os.File
if ctx.Flags.Bool("save") {
outFile := filepath.Base(fmt.Sprintf("%s_%s*.log", filepath.Base(ctx.Command.Name), filepath.Base(session.GetHostname())))
outFilePath, err = os.CreateTemp("", outFile)
if err != nil {
con.PrintErrorf("%s\n", err)
return
}
}
if aliasManifest.IsAssembly {
// Execute Assembly
ctrl := make(chan bool)
msg := fmt.Sprintf("Executing %s %s ...", ctx.Command.Name, extArgs)
con.SpinUntil(msg, ctrl)
executeAssemblyResp, err := con.Rpc.ExecuteAssembly(context.Background(), &sliverpb.ExecuteAssemblyReq{
Request: con.ActiveTarget.Request(ctx),
IsDLL: isDLL,
Process: processName,
Arguments: extArgs,
Assembly: binData,
Arch: ctx.Flags.String("arch"),
Method: ctx.Flags.String("method"),
ClassName: ctx.Flags.String("class"),
AppDomain: ctx.Flags.String("app-domain"),
ProcessArgs: processArgs,
PPid: uint32(ctx.Flags.Uint("ppid")),
InProcess: ctx.Flags.Bool("in-process"),
Runtime: ctx.Flags.String("runtime"),
AmsiBypass: ctx.Flags.Bool("amsi-bypass"),
EtwBypass: ctx.Flags.Bool("etw-bypass"),
})
ctrl <- true
<-ctrl
if err != nil {
con.PrintErrorf("%s\n", err)
return
}
if executeAssemblyResp.Response != nil && executeAssemblyResp.Response.Async {
con.AddBeaconCallback(executeAssemblyResp.Response.TaskID, func(task *clientpb.BeaconTask) {
err = proto.Unmarshal(task.Response, executeAssemblyResp)
if err != nil {
con.PrintErrorf("Failed to decode call ext response %s\n", err)
return
}
PrintAssemblyOutput(ctx.Command.Name, executeAssemblyResp, outFilePath, con)
})
con.PrintAsyncResponse(executeAssemblyResp.Response)
} else {
PrintAssemblyOutput(ctx.Command.Name, executeAssemblyResp, outFilePath, con)
}
} else if aliasManifest.IsReflective {
// Spawn DLL
ctrl := make(chan bool)
msg := fmt.Sprintf("Executing %s %s ...", ctx.Command.Name, extArgs)
con.SpinUntil(msg, ctrl)
spawnDllResp, err := con.Rpc.SpawnDll(context.Background(), &sliverpb.InvokeSpawnDllReq{
Request: con.ActiveTarget.Request(ctx),
Args: strings.Trim(extArgs, " "),
Data: binData,
ProcessName: processName,
EntryPoint: aliasManifest.Entrypoint,
Kill: true,
ProcessArgs: processArgs,
PPid: uint32(ctx.Flags.Uint("ppid")),
})
ctrl <- true
<-ctrl
if err != nil {
con.PrintErrorf("%s\n", err)
return
}
if spawnDllResp.Response != nil && spawnDllResp.Response.Async {
con.AddBeaconCallback(spawnDllResp.Response.TaskID, func(task *clientpb.BeaconTask) {
err = proto.Unmarshal(task.Response, spawnDllResp)
if err != nil {
con.PrintErrorf("Failed to decode call ext response %s\n", err)
return
}
PrintSpawnDLLOutput(ctx.Command.Name, spawnDllResp, outFilePath, con)
})
con.PrintAsyncResponse(spawnDllResp.Response)
} else {
PrintSpawnDLLOutput(ctx.Command.Name, spawnDllResp, outFilePath, con)
}
} else {
// Sideload
ctrl := make(chan bool)
msg := fmt.Sprintf("Executing %s %s ...", ctx.Command.Name, extArgs)
con.SpinUntil(msg, ctrl)
sideloadResp, err := con.Rpc.Sideload(context.Background(), &sliverpb.SideloadReq{
Request: con.ActiveTarget.Request(ctx),
Args: extArgs,
Data: binData,
EntryPoint: entryPoint,
ProcessName: processName,
Kill: true,
IsDLL: isDLL,
ProcessArgs: processArgs,
PPid: uint32(ctx.Flags.Uint("ppid")),
})
ctrl <- true
<-ctrl
if err != nil {
con.PrintErrorf("%s\n", err)
return
}
if sideloadResp.Response != nil && sideloadResp.Response.Async {
con.AddBeaconCallback(sideloadResp.Response.TaskID, func(task *clientpb.BeaconTask) {
err = proto.Unmarshal(task.Response, sideloadResp)
if err != nil {
con.PrintErrorf("Failed to decode call ext response %s\n", err)
return
}
PrintSideloadOutput(ctx.Command.Name, sideloadResp, outFilePath, con)
})
con.PrintAsyncResponse(sideloadResp.Response)
} else {
PrintSideloadOutput(ctx.Command.Name, sideloadResp, outFilePath, con)
}
}
}
// PrintSpawnDLLOutput - Prints the output of a spawn dll command
func PrintSpawnDLLOutput(cmdName string, spawnDllResp *sliverpb.SpawnDll, outFilePath *os.File, con *console.SliverConsoleClient) {
con.PrintInfof("%s output:\n%s", cmdName, spawnDllResp.GetResult())
if outFilePath != nil {
outFilePath.Write([]byte(spawnDllResp.GetResult()))
con.PrintInfof("Output saved to %s\n", outFilePath.Name())
}
}
// PrintSideloadOutput - Prints the output of a sideload command
func PrintSideloadOutput(cmdName string, sideloadResp *sliverpb.Sideload, outFilePath *os.File, con *console.SliverConsoleClient) {
con.PrintInfof("%s output:\n%s", cmdName, sideloadResp.GetResult())
if outFilePath != nil {
outFilePath.Write([]byte(sideloadResp.GetResult()))
con.PrintInfof("Output saved to %s\n", outFilePath.Name())
}
}
// PrintAssemblyOutput - Prints the output of an execute-assembly command
func PrintAssemblyOutput(cmdName string, execAsmResp *sliverpb.ExecuteAssembly, outFilePath *os.File, con *console.SliverConsoleClient) {
con.PrintInfof("%s output:\n%s", cmdName, string(execAsmResp.GetOutput()))
if outFilePath != nil {
outFilePath.Write(execAsmResp.GetOutput())
con.PrintInfof("Output saved to %s\n", outFilePath.Name())
}
}
func cmdExists(name string, app *grumble.App) bool {
for _, c := range app.Commands().All() {
if name == c.Name {
return true
}
}
return false
}