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analyze.js
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analyze.js
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const lib = require("./lib");
const loop_rewriter = require("./loop_rewriter");
const equality_rewriter = require("./equality_rewriter");
const escodegen = require("escodegen");
const acorn = require("acorn");
const fs = require("fs");
const iconv = require("iconv-lite");
const path = require("path");
const {VM} = require("vm2");
const child_process = require("child_process");
const argv = require("./argv.js").run;
const jsdom = require("jsdom").JSDOM;
const dom = new jsdom(`<html><head></head><body></body></html>`);
const { DOMParser } = require('xmldom');
const filename = process.argv[2];
// JScriptMemberFunctionStatement plugin registration
// Plugin system is now different in Acorn 8.*, so commenting out.
//require("./patches/prototype-plugin.js")(acorn);
lib.debug("Analysis launched: " + JSON.stringify(process.argv));
lib.verbose("Box-js version: " + require("./package.json").version);
let git_path = path.join(__dirname, ".git");
if (fs.existsSync(git_path) && fs.lstatSync(git_path).isDirectory()) {
lib.verbose("Commit: " + fs.readFileSync(path.join(__dirname, ".git/refs/heads/master"), "utf8").replace(/\n/, ""));
} else {
lib.verbose("No git folder found.");
}
lib.verbose(`Analyzing ${filename}`, false);
const sampleBuffer = fs.readFileSync(filename);
let encoding;
if (argv.encoding) {
lib.debug("Using argv encoding");
encoding = argv.encoding;
} else {
lib.debug("Using detected encoding");
encoding = require("jschardet").detect(sampleBuffer).encoding;
if (encoding === null) {
lib.warning("jschardet (v" + require("jschardet/package.json").version + ") couldn't detect encoding, using UTF-8");
encoding = "utf8";
} else {
lib.debug("jschardet (v" + require("jschardet/package.json").version + ") detected encoding " + encoding);
}
}
let code = iconv.decode(sampleBuffer, encoding);
let rawcode;
if (argv["activex-as-ioc"]) {
rawcode = iconv.decode(sampleBuffer, encoding);
}
/*
if (code.match("<job") || code.match("<script")) { // The sample may actually be a .wsf, which is <job><script>..</script><script>..</script></job>.
lib.debug("Sample seems to be WSF");
code = code.replace(/<\??\/?\w+( [\w=\"\']*)*\??>/g, ""); // XML tags
code = code.replace(/<!\[CDATA\[/g, "");
code = code.replace(/\]\]>/g, "");
}
*/
function lacksBinary(name) {
const path = child_process.spawnSync("command", ["-v", name], {
shell: true
}).stdout;
return path.length === 0;
}
function escapeRegExp(string) {
return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'); // $& means the whole matched string
}
function stripSingleLineComments(s) {
const lines = s.split("\n");
var r = "";
for (const line of lines) {
var lineStrip = line.trim() + "\r";
for (const subLine of lineStrip.split("\r")) {
// Full line comment?
var subLineStrip = subLine.trim();
if (subLineStrip.startsWith("//")) continue;
r += subLineStrip + "\n";
}
}
return r;
}
function isAlphaNumeric(str) {
var code, i;
if (str.length == 0) return false;
code = str.charCodeAt(0);
if (!(code > 47 && code < 58) && // numeric (0-9)
!(code > 64 && code < 91) && // upper alpha (A-Z)
!(code > 96 && code < 123)) { // lower alpha (a-z)
return false;
}
return true;
};
function hideStrs(s) {
var inStrSingle = false;
var inStrDouble = false;
var inStrBackTick = false;
var inComment = false;
var inCommentSingle = false;
var inRegex = false
var oldInRegex = false
var currStr = undefined;
var prevChar = "";
var prevPrevChar = "";
var allStrs = {};
var escapedSlash = false;
var prevEscapedSlash = false;
var counter = 1000000;
var r = "";
var skip = false;
var justExitedComment = false;
var slashSubstr = ""
var resetSlashes = false;
var justStartedRegex = false;
var inSquareBrackets = false;
s = stripSingleLineComments(s);
// For debugging.
var window = " ";
// Special case. Regex uses like '/.../["test"]' are really hard
// to deal with. Hide all '["test"]' instances.
var tmpName = "HIDE_" + counter++;
s = s.replace(/\["test"\]/g, tmpName);
allStrs[tmpName] = '["test"]';
tmpName = "HIDE_" + counter++;
s = s.replace(/\['test'\]/g, tmpName);
allStrs[tmpName] = "['test']";
// Similar to the above, obfuscator.io constructs like
// '/.../[0x_fff(' are also really hard to deal with. Replace
// those also.
tmpName = "HIDE_" + counter++;
// Ony match exprs that start with the '/' and keep the '/' in the
// code to close out the regex. We are doing this because
// Replacement name must start with HIDE_.
s = s.replace(/\/\[_0x/g, "/" + tmpName);
allStrs[tmpName] = "[_0x";
//console.log("prevprev,prev,curr,dbl,single,commsingl,comm,regex,oldinregex,slash,justexitcom");
for (let i = 0; i < s.length; i++) {
// Track consecutive backslashes. We use this to tell if the
// current back slash has been escaped (even # of backslashes)
// or is escaping the next character (odd # of slashes).
if (prevChar == "\\" && (slashSubstr.length == 0)) {
slashSubstr = "\\";
}
else if (prevChar == "\\" && (slashSubstr.length > 0)) {
slashSubstr += "\\";
}
else if (prevChar != "\\") {
slashSubstr = "";
}
// Backslash escaping gets 'reset' when hitting a space.
var currChar = s[i];
if ((currChar == " ") && slashSubstr) {
slashSubstr = "";
resetSlashes = true;
}
// Debugging.
//window = window.slice(1,) + currChar;
//console.log(window);
// Start /* */ comment?
var oldInComment = inComment;
inComment = inComment || ((prevChar == "/") && (currChar == "*") && !inStrDouble && !inStrSingle && !inCommentSingle && !inStrBackTick && (!inRegex || !oldInRegex));
//console.log(JSON.stringify([prevPrevChar, prevChar, currChar, inStrDouble, inStrSingle, inCommentSingle, inComment, inRegex, oldInRegex, slashSubstr, justExitedComment]))
//console.log(r);
// In /* */ comment?
if (inComment) {
// We are stripping /* */ comments, so drop the '/' if we
// just entered the comment.
if (oldInComment != inComment) {
inRegex = false;
r = r.slice(0, -1);
}
// Dropping /* */ comments, so don't save current char.
// Out of comment?
if ((prevChar == "*") && (currChar == "/")) {
inComment = false;
// Handle FP single line comment detection for things
// like '/* comm1 *//* comm2 */'.
justExitedComment = true;
}
// Keep going until we leave the comment. Recognizing some
// constructs is hard with whitespace, so strip that out
// when tracking previous characters.
if (currChar != " ") {
prevPrevChar = prevChar;
prevChar = currChar;
}
continue;
}
// Start // comment?
inCommentSingle = inCommentSingle || ((prevChar == "/") && (currChar == "/") && !inStrDouble && !inStrSingle && !inComment && !justExitedComment && !inStrBackTick);
// Could have falsely jumped out of a /**/ comment if it contains a //.
if ((prevChar == "/") && (currChar == "/") && !inComment && justExitedComment) {
inComment = true;
justExitedComment = false;
continue
}
justExitedComment = false;
// In // comment?
if (inCommentSingle) {
// Not in a regex if we are in a '// ...' comment.
inRegex = false;
// Save comment text unmodified.
r += currChar;
// Out of comment?
if ((currChar == "\n") || (currChar == "\r")) {
inCommentSingle = false;
}
// Keep going until we leave the comment.
if (currChar != " ") {
prevPrevChar = prevChar;
prevChar = currChar;
}
continue;
}
// Start /.../ regex expression?
oldInRegex = inRegex;
// Assume that regex expressions can't be preceded by ')' or
// an alphanumeric character. This is to try to tell divisiion
// from the start of a regex.
inRegex = inRegex || ((prevChar != "/") && (prevChar != ")") && !isAlphaNumeric(prevChar) &&
(currChar == "/") && !inStrDouble && !inStrSingle && !inComment && !inCommentSingle && !inStrBackTick);
// In /.../ regex expression?
if (inRegex) {
// Save regex unmodified.
r += currChar;
// In character set (square brackets)?
if (currChar == "[") inSquareBrackets = true;
if (currChar == "]") inSquareBrackets = false;
// Out of regex?
//
// Unescaped '/' can appear in a regex (nice). Try to
// guess whether the '/' actually ends the regex based on
// the char after the '/'. Add chars that CANNOT appear
// after a regex def as needed.
//
// ex. var f=/[!"#$%&'()*+,/\\:;<=>?@[\]^`{|}~]/g;
if (!justStartedRegex &&
!inSquareBrackets &&
(prevChar == "/") && (prevPrevChar != "\\") &&
((slashSubstr.length % 2) == 0) &&
("\\:[]?".indexOf(currChar) == -1)) {
inRegex = false;
}
// Track seeing the '/' starting the regex.
justStartedRegex = !oldInRegex;
// Keep going until we leave the regex.
if (currChar != " ") {
prevPrevChar = prevChar;
prevChar = currChar;
}
if (resetSlashes) prevChar = " ";
resetSlashes = false;
continue;
}
// Looking at an escaped back slash (1 char back)?
escapedSlash = (prevChar == "\\" && prevPrevChar == "\\");
// Start/end single quoted string?
if ((currChar == "'") &&
((prevChar != "\\") || ((prevChar == "\\") && ((slashSubstr.length % 2) == 0) && inStrSingle)) &&
!inStrDouble && !inStrBackTick) {
// Switch being in/out of string.
inStrSingle = !inStrSingle;
// Finished up a string we were tracking?
if (!inStrSingle) {
currStr += "'";
const strName = "HIDE_" + counter++;
allStrs[strName] = currStr;
r += strName;
skip = true;
}
else {
currStr = "";
}
};
// Start/end double quoted string?
if ((currChar == '"') &&
((prevChar != "\\") || ((prevChar == "\\") && ((slashSubstr.length % 2) == 0) && inStrDouble)) &&
!inStrSingle && !inStrBackTick && !inCommentSingle && !inComment && !inRegex) {
// Switch being in/out of string.
inStrDouble = !inStrDouble;
// Finished up a string we were tracking?
if (!inStrDouble) {
currStr += '"';
const strName = "HIDE_" + counter++;
allStrs[strName] = currStr;
r += strName;
skip = true;
}
else {
currStr = "";
}
};
// Start/end backtick quoted string?
if ((currChar == '`') &&
((prevChar != "\\") || ((prevChar == "\\") && escapedSlash && !prevEscapedSlash && inStrBackTick)) &&
!inStrSingle && !inStrDouble && !inCommentSingle && !inComment && !inRegex) {
// Switch being in/out of string.
inStrBackTick = !inStrBackTick;
// Finished up a string we were tracking?
if (!inStrBackTick) {
currStr += '`';
const strName = "HIDE_" + counter++;
allStrs[strName] = currStr;
r += strName;
skip = true;
}
else {
currStr = "";
}
};
// Save the current character if we are tracking a string.
if (inStrDouble || inStrSingle || inStrBackTick) {
currStr += currChar;
}
// Not in a string. Just save the original character in the
// result string.
else if (!skip) {
r += currChar;
};
skip = false;
// Track what is now the previous character so we can handle
// escaped quotes in strings.
prevPrevChar = prevChar;
if (currChar != " ") prevChar = currChar;
if (resetSlashes) prevChar = " ";
resetSlashes = false;
prevEscapedSlash = escapedSlash;
}
//console.log(JSON.stringify([prevPrevChar, prevChar, currChar, inStrDouble, inStrSingle, inCommentSingle, inComment, inRegex, slashSubstr, justExitedComment]))
return [r, allStrs];
}
function unhideStrs(s, map) {
// Replace each HIDE_NNNN with the hidden string.
var oldPos = 0;
var currPos = s.indexOf("HIDE_");
var r = "";
var done = (currPos < 0);
while (!done) {
// Add in the previous non-hidden string contents.
r += s.slice(oldPos, currPos);
// Pull out the name of the hidden string.
var tmpPos = currPos + "HIDE_".length + 7;
// Get the original string.
var hiddenName = s.slice(currPos, tmpPos);
var origVal = map[hiddenName];
// Add in the unhidden string.
r += origVal;
// Move to the next string to unhide.
oldPos = tmpPos;
currPos = s.slice(tmpPos).indexOf("HIDE_");
done = (currPos < 0);
currPos = tmpPos + currPos;
}
// Add in remaining original string that had nothing hidden.
r += s.slice(tmpPos);
// Done.
return r;
}
// JScript lets you stick the actual code to run in a conditional
// comment like '/*@if(@_jscript_version >= 4)....*/'. If there,
// extract that code out.
function extractCode(code) {
// See if we can pull code out from conditional comments.
// /*@if(@_jscript_version >= 4) ... @else @*/
// /*@if(1) ... @end@*/
//
// /*@cc_on
// @if(1) ... @end@*/
const commentPat = /\/\*(?:@cc_on\s+)?@if\s*\([^\)]+\)(.+?)@(else|end)\s*@\s*\*\//s
const codeMatch = code.match(commentPat);
if (!codeMatch) {
return code;
}
var r = codeMatch[1];
lib.info("Extracted code to analyze from conditional JScript comment.");
return r;
}
function rewrite(code, useException=false) {
//console.log("!!!! CODE: 0 !!!!");
//console.log(code);
//console.log("!!!! CODE: 0 !!!!");
// box-js is assuming that the JS will be run on Windows with cscript or wscript.
// Neither of these engines supports strict JS mode, so remove those calls from
// the code.
code = code.toString().replace(/"use strict"/g, '"STRICT MODE NOT SUPPORTED"');
code = code.toString().replace(/'use strict'/g, "'STRICT MODE NOT SUPPORTED'");
// The following 2 code rewrites should not be applied to patterns
// in string literals. Hide the string literals first.
//
// This also strips all comments.
var counter = 1000000;
const [newCode, strMap] = hideStrs(code);
code = newCode;
//console.log("!!!! CODE: 1 !!!!");
//console.log(code);
//console.log("!!!! CODE: 1 !!!!");
//console.log("!!!! STRMAP !!!!");
//console.log(strMap);
//console.log("!!!! STRMAP !!!!");
// WinHTTP ActiveX objects let you set options like 'foo.Option(n)
// = 12'. Acorn parsing fails on these with a assigning to rvalue
// syntax error, so rewrite things like this so we can parse
// (replace these expressions with comments). We have to do this
// with regexes rather than modifying the parse tree since these
// expressions cannot be parsed by acorn.
var rvaluePat = /[\n;][^\n^;]*?\([^\n^;]+?\)\s*=[^=^>][^\n^;]+?\r?(?=[;])/g;
code = code.toString().replace(rvaluePat, ';/* ASSIGNING TO RVALUE */');
rvaluePat = /[\n;][^\n^;]*?\([^\n^;]+?\)\s*=[^=^>][^\n^;]+?\r?(?=[\n])/g;
code = code.toString().replace(rvaluePat, ';// ASSIGNING TO RVALUE');
//console.log("!!!! CODE: 2 !!!!");
//console.log(code);
//console.log("!!!! CODE: 2 !!!!");
// Now unhide the string literals.
code = unhideStrs(code, strMap);
//console.log("!!!! CODE: 3 !!!!");
//console.log(code);
//console.log("!!!! CODE: 3 !!!!");
// Some samples (for example that use JQuery libraries as a basis to which to
// add malicious code) won't emulate properly for some reason if there is not
// an assignment line at the start of the code. Add one here (this should not
// change the behavior of the code).
code = "__bogus_var_name__ = 12;\n\n" + code;
if (code.match("@cc_on")) {
lib.debug("Code uses conditional compilation");
if (!argv["no-cc_on-rewrite"]) {
code = code
.replace(/\/\*@cc_on/gi, "")
.replace(/@cc_on/gi, "")
.replace(/\/\*@/g, "\n").replace(/@\*\//g, "\n");
// "@if" processing requires m4 and cc, but don't require them otherwise
if (/@if/.test(code)) {
/*
"@if (cond) source" becomes "\n _boxjs_if(cond)" with JS
"\n _boxjs_if(cond)" becomes "\n #if (cond) \n source" with m4
"\n #if (cond) \n source" becomes "source" with the C preprocessor
*/
code = code
.replace(/@if\s*/gi, "\n_boxjs_if")
.replace(/@elif\s*/gi, "\n_boxjs_elif")
.replace(/@else/gi, "\n#else\n")
.replace(/@end/gi, "\n#endif\n")
.replace(/@/g, "_boxjs_at");
// Require m4, cc
if (lacksBinary("cc")) lib.kill("You must install a C compiler (executable 'cc' not found).");
if (lacksBinary("m4")) lib.kill("You must install m4.");
code = `
define(\`_boxjs_if', #if ($1)\n)
define(\`_boxjs_elif', #elif ($1)\n)
` + code;
lib.info(" Replacing @cc_on statements (use --no-cc_on-rewrite to skip)...", false);
const outputM4 = child_process.spawnSync("m4", [], {
input: code
});
const outputCc = child_process.spawnSync("cc", [
"-E", "-P", // preprocess, don't compile
"-xc", // read from stdin, lang: c
"-D_boxjs_at_x86=1", "-D_boxjs_at_win16=0", "-D_boxjs_at_win32=1", "-D_boxjs_at_win64=1", // emulate Windows 32 bit
"-D_boxjs_at_jscript=1",
"-o-", // print to stdout
"-", // read from stdin
], {
input: outputM4.stdout.toString("utf8"),
});
code = outputCc.stdout.toString("utf8");
}
code = code.replace(/_boxjs_at/g, "@");
} else {
lib.warn(
`The code appears to contain conditional compilation statements.
If you run into unexpected results, try uncommenting lines that look like
/*@cc_on
<JavaScript code>
@*/
`
);
}
}
if (!argv["no-rewrite"]) {
try {
lib.verbose("Rewriting code...", false);
if (argv["dumb-concat-simplify"]) {
lib.verbose(" Simplifying \"dumb\" concatenations (remove --dumb-concat-simplify to skip)...", false);
code = code.replace(/'[ \r\n]*\+[ \r\n]*'/gm, "");
code = code.replace(/"[ \r\n]*\+[ \r\n]*"/gm, "");
}
let tree;
try {
//console.log("!!!! CODE FINAL !!!!");
//console.log(code);
//console.log("!!!! CODE FINAL !!!!");
tree = acorn.parse(code, {
ecmaVersion: "latest",
allowReturnOutsideFunction: true, // used when rewriting function bodies
plugins: {
// enables acorn plugin needed by prototype rewrite
JScriptMemberFunctionStatement: !argv["no-rewrite-prototype"],
},
});
} catch (e) {
if (useException) return 'throw("Parse Error")';
lib.error("Couldn't parse with Acorn:");
lib.error(e);
lib.error("");
if (filename.match(/jse$/)) {
lib.error(
`This appears to be a JSE (JScript.Encode) file.
Please compile the decoder and decode it first:
cc decoder.c -o decoder
./decoder ${filename} ${filename.replace(/jse$/, "js")}
`
);
} else {
lib.error(
// @@@ Emacs JS mode does not properly parse this block.
//`This doesn't seem to be a JavaScript/WScript file.
//If this is a JSE file (JScript.Encode), compile
//decoder.c and run it on the file, like this:
//
//cc decoder.c -o decoder
//./decoder ${filename} ${filename}.js
//
//`
"Decode JSE. 'cc decoder.c -o decoder'. './decoder ${filename} ${filename}.js'"
);
}
process.exit(4);
return;
}
// Loop rewriting is looking for loops in the original unmodified code so
// do this before any other modifications.
if (argv["rewrite-loops"]) {
lib.verbose(" Rewriting loops...", false);
traverse(tree, loop_rewriter.rewriteSimpleWaitLoop);
traverse(tree, loop_rewriter.rewriteSimpleControlLoop);
traverse(tree, loop_rewriter.rewriteLongWhileLoop);
};
// Rewrite == checks so that comparisons of the current script name to
// a hard coded script name always return true.
if (argv["loose-script-name"] && code.includes("==")) {
lib.verbose(" Rewriting == checks...", false);
traverse(tree, equality_rewriter.rewriteScriptCheck);
}
if (argv.preprocess) {
lib.verbose(` Preprocessing with uglify-es v${require("uglify-es/package.json").version} (remove --preprocess to skip)...`, false);
const unsafe = !!argv["unsafe-preprocess"];
lib.debug("Unsafe preprocess: " + unsafe);
const result = require("uglify-es").minify(code, {
parse: {
bare_returns: true, // used when rewriting function bodies
},
compress: {
passes: 3,
booleans: true,
collapse_vars: true,
comparisons: true,
conditionals: true,
dead_code: true,
drop_console: false,
evaluate: true,
if_return: true,
inline: true,
join_vars: false, // readability
keep_fargs: unsafe, // code may rely on Function.length
keep_fnames: unsafe, // code may rely on Function.prototype.name
keep_infinity: true, // readability
loops: true,
negate_iife: false, // readability
properties: true,
pure_getters: false, // many variables are proxies, which don't have pure getters
/* If unsafe preprocessing is enabled, tell uglify-es that Math.* functions
* have no side effects, and therefore can be removed if the result is
* unused. Related issue: mishoo/UglifyJS2#2227
*/
pure_funcs: unsafe ?
// https://stackoverflow.com/a/10756976
Object.getOwnPropertyNames(Math).map(key => `Math.${key}`) : null,
reduce_vars: true,
/* Using sequences (a; b; c; -> a, b, c) provides some performance benefits
* (https://github.com/CapacitorSet/box-js/commit/5031ba7114b60f1046e53b542c0e4810aad68a76#commitcomment-23243778),
* but it makes code harder to read. Therefore, this behaviour is disabled.
*/
sequences: false,
toplevel: true,
typeofs: false, // typeof foo == "undefined" -> foo === void 0: the former is more readable
unsafe,
unused: true,
},
output: {
beautify: true,
comments: true,
},
});
if (result.error) {
lib.error("Couldn't preprocess with uglify-es: " + JSON.stringify(result.error));
} else {
code = result.code;
}
}
if (!argv["no-rewrite-prototype"]) {
lib.verbose(" Replacing `function A.prototype.B()` (use --no-rewrite-prototype to skip)...", false);
traverse(tree, function(key, val) {
if (!val) return;
if (val.type !== "FunctionDeclaration" &&
val.type !== "FunctionExpression") return;
if (!val.id) return;
if (val.id.type !== "MemberExpression") return;
r = require("./patches/prototype.js")(val);
return r;
});
}
if (!argv["no-hoist-prototype"]) {
lib.verbose(" Hoisting `function A.prototype.B()` (use --no-hoist-prototype to skip)...", false);
hoist(tree);
}
if (argv["function-rewrite"]) {
lib.verbose(" Rewriting functions (remove --function-rewrite to skip)...", false);
traverse(tree, function(key, val) {
if (key !== "callee") return;
if (val.autogenerated) return;
switch (val.type) {
case "MemberExpression":
return require("./patches/this.js")(val.object, val);
default:
return require("./patches/nothis.js")(val);
}
});
}
if (!argv["no-typeof-rewrite"]) {
lib.verbose(" Rewriting typeof calls (use --no-typeof-rewrite to skip)...", false);
traverse(tree, function(key, val) {
if (!val) return;
if (val.type !== "UnaryExpression") return;
if (val.operator !== "typeof") return;
if (val.autogenerated) return;
return require("./patches/typeof.js")(val.argument);
});
}
if (!argv["no-eval-rewrite"]) {
lib.verbose(" Rewriting eval calls (use --no-eval-rewrite to skip)...", false);
traverse(tree, function(key, val) {
if (!val) return;
if (val.type !== "CallExpression") return;
if (val.callee.type !== "Identifier") return;
if (val.callee.name !== "eval") return;
return require("./patches/eval.js")(val.arguments);
});
}
if (!argv["no-catch-rewrite"]) { // JScript quirk
lib.verbose(" Rewriting try/catch statements (use --no-catch-rewrite to skip)...", false);
traverse(tree, function(key, val) {
if (!val) return;
if (val.type !== "TryStatement") return;
if (!val.handler) return;
if (val.autogenerated) return;
return require("./patches/catch.js")(val);
});
}
code = escodegen.generate(tree);
//console.log("!!!! CODE !!!!");
//console.log(code);
// The modifications may have resulted in more concatenations, eg. "a" + ("foo", "b") + "c" -> "a" + "b" + "c"
if (argv["dumb-concat-simplify"]) {
lib.verbose(" Simplifying \"dumb\" concatenations (remove --dumb-concat-simplify to skip)...", false);
code = code.replace(/'[ \r\n]*\+[ \r\n]*'/gm, "");
code = code.replace(/"[ \r\n]*\+[ \r\n]*"/gm, "");
}
lib.verbose("Rewritten successfully.", false);
} catch (e) {
if (argv["ignore-rewrite-errors"]) {
lib.warning("Code rewriting failed. Analyzing original sample.");
}
else {
console.log("An error occurred during rewriting:");
console.log(e);
process.exit(3);
}
}
}
return code;
}
// Extract the actual code to analyze from conditional JScript
// comments if needed.
if (argv["extract-conditional-code"]) {
code = extractCode(code);
}
// Track if we are throttling large/frequent file writes.
if (argv["throttle-writes"]) {
lib.throttleFileWrites(true);
};
// Track if we are throttling frequent command executions.
if (argv["throttle-commands"]) {
lib.throttleCommands(true);
};
// Rewrite the code if needed.
code = rewrite(code);
// prepend extra JS containing mock objects in the given file(s) onto the code
if (argv["prepended-code"]) {
var prependedCode = ""
var files = []
// get all the files in the directory and sort them alphebetically
var isDir = false;
try {
isDir = fs.lstatSync(argv["prepended-code"]).isDirectory();
}
catch (e) {}
if (isDir) {
dir_files = fs.readdirSync(argv["prepended-code"]);
for (var i = 0; i < dir_files.length; i++) {
files.push(path.join(argv["prepended-code"], dir_files[i]))
}
// make sure we're adding mock code in the right order
files.sort()
} else {
// Use default boilerplate code?
if (argv["prepended-code"] == "default") {
const defaultBP = __dirname + "/boilerplate.js";
files.push(defaultBP);
}
else {
files.push(argv["prepended-code"]);
}
}
for (var i = 0; i < files.length; i++) {
prependedCode += fs.readFileSync(files[i], 'utf-8') + "\n\n"
}
code = prependedCode + "\n\n" + code
}
// prepend patch code, unless it is already there.
if (!code.includes("let __PATCH_CODE_ADDED__ = true;")) {
code = fs.readFileSync(path.join(__dirname, "patch.js"), "utf8") + code;
}
else {
console.log("Patch code already added.");
}
// append more code
code += "\n\n" + fs.readFileSync(path.join(__dirname, "appended-code.js"));
lib.logJS(code);
Array.prototype.Count = function() {
return this.length;
};
// Set the fake scripting engine to report.
var fakeEngineShort = "wscript.exe"
if (argv["fake-script-engine"]) {
fakeEngineShort = argv["fake-script-engine"];
}
var fakeEngineFull = "C:\\WINDOWS\\system32\\" + fakeEngineShort;
// Fake command line options can be set with the --fake-cl-args option.
var commandLineArgs = [];
if (argv["fake-cl-args"]) {
commandLineArgs = argv["fake-cl-args"].split(",");
}
// Fake sample file name can be set with the --fake-sample-name option.
var sampleName = "CURRENT_SCRIPT_IN_FAKED_DIR.js";
var sampleFullName = "C:\Users\\Sysop12\\AppData\\Roaming\\Microsoft\\Templates\\" + sampleName;
if (argv["fake-sample-name"]) {
// Sample name with full path?
var dirChar = undefined;
if (argv["fake-sample-name"].indexOf("\\") >= 0) {
dirChar = "\\";
}
if (argv["fake-sample-name"].indexOf("/") >= 0) {
dirChar = "/";
}
if (dirChar) {
// Break out the immediate sample name and full name.
sampleName = argv["fake-sample-name"].slice(argv["fake-sample-name"].lastIndexOf(dirChar) + 1);
sampleFullName = argv["fake-sample-name"];
}
else {
sampleName = argv["fake-sample-name"];
sampleFullName = "C:\Users\\Sysop12\\AppData\\Roaming\\Microsoft\\Templates\\" + sampleName;
}
lib.logIOC("Sample Name",
{"sample-name": sampleName, "sample-name-full": sampleFullName},
"Using fake sample file name " + sampleFullName + " when analyzing.");
}
else if (argv["real-script-name"]) {
sampleName = path.basename(filename);
sampleFullName = filename;
lib.logIOC("Sample Name",
{"sample-name": sampleName, "sample-name-full": sampleFullName},
"Using real sample file name " + sampleFullName + " when analyzing.");
}
else {
lib.logIOC("Sample Name",
{"sample-name": sampleName, "sample-name-full": sampleFullName},
"Using standard fake sample file name " + sampleFullName + " when analyzing.");
}
// Fake up the WScript object for Windows JScript.
var wscript_proxy = new Proxy({
arguments: new Proxy((n) => commandLineArgs[n], {
get: function(target, name) {
name = name.toString().toLowerCase();
switch (name) {
case "unnamed":
return commandLineArgs;
case "length":
return commandLineArgs.length;
case "showUsage":
return {
typeof: "unknown",
};
case "named":
return commandLineArgs;
default:
return new Proxy(
target[name], {
get: (target, name) => name.toLowerCase() === "typeof" ? "unknown" : target[name],
}
);
}
},
}),
buildversion: "1234",
interactive: true,
fullname: fakeEngineFull,
name: fakeEngineShort,
path: "C:\\TestFolder\\",
scriptfullname: sampleFullName,
scriptname: sampleName,
quit: function() {
lib.logIOC("WScript", "Quit()", "The sample explicitly called WScript.Quit().");
//console.trace()
if ((!argv["ignore-wscript-quit"]) || lib.doWscriptQuit()) {
process.exit(0);
}
},
get stderr() {
lib.error("WScript.StdErr not implemented");
},
get stdin() {
lib.error("WScript.StdIn not implemented");
},
get stdout() {
lib.error("WScript.StdOut not implemented");
},
version: "5.8",
get connectobject() {
lib.error("WScript.ConnectObject not implemented");
},
createobject: ActiveXObject,
get disconnectobject() {
lib.error("WScript.DisconnectObject not implemented");
},
echo() {},
get getobject() {
lib.error("WScript.GetObject not implemented");
},
// Note that Sleep() is implemented in patch.js because it requires
// access to the variable _globalTimeOffset, which belongs to the script
// and not to the emulator.
[Symbol.toPrimitive]: () => "Windows Script Host",
tostring: "Windows Script Host",
}, {
get(target, prop) {
// For whatever reasons, WScript.* properties are case insensitive.
if (typeof prop === "string")
prop = prop.toLowerCase();
return target[prop];
}
});
const sandbox = {
saveAs : function(data, fname) {
// TODO: If Blob need to extract the data.
lib.writeFile(fname, data);
},
setInterval : function() {},
setTimeout : function(func, time) {
// The interval should be an int, so do a basic check for int.
if ((typeof(time) !== "number") || (time == null)) {
throw("time is not a number.");
}
// Just call the function immediately, no waiting.
if (typeof(func) === "function") {
func();
}
else {
throw("Callback must be a function");
}
},
logJS: lib.logJS,
logIOC: lib.logIOC,
logUrl: lib.logUrl,
ActiveXObject,
dom,
alert: (x) => {},
InstallProduct: (x) => {
lib.logUrl("InstallProduct", x);
},
console: {
//log: (x) => console.log(x),
//log: (x) => lib.info("Script output: " + JSON.stringify(x)),
log: function (x) {
lib.info("Script output: " + x);