{"id":7855,"date":"2021-10-09T06:44:16","date_gmt":"2021-10-09T06:44:16","guid":{"rendered":"https:\/\/www.hexacorn.com\/blog\/?p=7855"},"modified":"2021-10-09T06:46:56","modified_gmt":"2021-10-09T06:46:56","slug":"trololololobin-and-other-lolololocoasters","status":"publish","type":"post","link":"https:\/\/www.hexacorn.com\/blog\/2021\/10\/09\/trololololobin-and-other-lolololocoasters\/","title":{"rendered":"Trololololobin and other lolololocoasters"},"content":{"rendered":"\n<p>In  my older <a href=\"https:\/\/twitter.com\/Hexacorn\/status\/1426294851449073666?s=20\">tweet<\/a> I gave an example of a surgical way to inject process into a chain of executed programs and launch them at a predetermined position in a great-great-great\u2026.grand-parent-child relationship by using the <em>start <\/em>command:<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">start \/b \"\" start \/b \"\" start \/b \"\" start \/b \"\" start \/b \"\" start \/b notepad.exe<\/pre>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><a href=\"https:\/\/www.hexacorn.com\/blog\/wp-content\/uploads\/2021\/10\/start.png\"><img decoding=\"async\" loading=\"lazy\" width=\"202\" height=\"146\" src=\"https:\/\/www.hexacorn.com\/blog\/wp-content\/uploads\/2021\/10\/start.png\" alt=\"\" class=\"wp-image-7856\"\/><\/a><\/figure><\/div>\n\n\n\n<p>Many Lolbins focus on loading DLLs, downloading files, etc. I was wondering if there is a class of Lolbins that could be used to generate this kinda process tree. The idea being that if we can find it, we can create more &#8216;signed executable&#8217; chains and potentially disrupt parent-child relationship-based EDR detections.<\/p>\n\n\n\n<p>After combing through my file collection I found one candidate and I suspect there will be others.<\/p>\n\n\n\n<p>The Toshiba&#8217;s signed <em>tinstall.exe<\/em> is an executable that is a part of many installs from this company. When launched, it spawns a child process which is a next step of the installation. The peculiar way it is doing it is providing us the feature I described above. When launched, it takes its own file name, and appends &#8216;wb&#8217; to it, and then launches a program with that newly created name. Under normal circumstances, the name of the spawned process will be <em>tinstallwb.exe<\/em>. <\/p>\n\n\n\n<p>By placing a number of copies of <em>tinstall.exe<\/em> in files named <em>.exe<\/em>, <em>wb.exe<\/em>, <em>wbwb.exe<\/em>, <em>wbwbwb.exe<\/em>, etc. we can build a chain of process spawned from signed executables with the <em>wbwbwbwbwbwbwb.exe<\/em> being the final &#8216;payload&#8217;:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/www.hexacorn.com\/blog\/wp-content\/uploads\/2021\/10\/tinstall.png\"><img decoding=\"async\" loading=\"lazy\" width=\"580\" height=\"200\" src=\"https:\/\/www.hexacorn.com\/blog\/wp-content\/uploads\/2021\/10\/tinstall.png\" alt=\"\" class=\"wp-image-7857\" srcset=\"https:\/\/www.hexacorn.com\/blog\/wp-content\/uploads\/2021\/10\/tinstall.png 580w, https:\/\/www.hexacorn.com\/blog\/wp-content\/uploads\/2021\/10\/tinstall-300x103.png 300w\" sizes=\"(max-width: 580px) 100vw, 580px\" \/><\/a><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>In my older tweet I gave an example of a surgical way to inject process into a chain of executed programs and launch them at a predetermined position in a great-great-great\u2026.grand-parent-child relationship by using the start command: start \/b &#8220;&#8221; &hellip; <a href=\"https:\/\/www.hexacorn.com\/blog\/2021\/10\/09\/trololololobin-and-other-lolololocoasters\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[56,64],"tags":[],"_links":{"self":[{"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/posts\/7855"}],"collection":[{"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/comments?post=7855"}],"version-history":[{"count":3,"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/posts\/7855\/revisions"}],"predecessor-version":[{"id":7860,"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/posts\/7855\/revisions\/7860"}],"wp:attachment":[{"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/media?parent=7855"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/categories?post=7855"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hexacorn.com\/blog\/wp-json\/wp\/v2\/tags?post=7855"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}