{ "id": "f231912f-b8b6-47eb-867a-390c7c7781b8", "created_at": "2026-04-06T00:13:07.151502Z", "updated_at": "2026-04-10T03:20:35.79788Z", "deleted_at": null, "sha1_hash": "feed7d58eb4e93a05219ed80984b4ec02361c2fd", "title": "Latrodectus Malware Analysis - Decoding Obfuscated Malware By Removing Junk Comments", "llm_title": "", "authors": "", "file_creation_date": "0001-01-01T00:00:00Z", "file_modification_date": "0001-01-01T00:00:00Z", "file_size": 2120187, "plain_text": "Latrodectus Malware Analysis - Decoding Obfuscated Malware By\r\nRemoving Junk Comments\r\nBy Matthew\r\nPublished: 2024-03-25 ยท Archived: 2026-04-05 19:03:21 UTC\r\nThis post will dive into a Latrodectus loader that leverages junk comments and wmi commands to obfuscate\r\nfunctionality and download a remote .msi file.\r\nThere are three \"stages\" to this sample, which can be decoded through a combination of regular expressions and\r\nCyberChef.\r\nObtaining Initial Sample\r\nThe initial sample can be found on Malware Bazaar and was initially uploaded by pr0xylife\r\nSHA256: 71fb25cc4c05ce9dd94614ed781d85a50dccf69042521abc6782d48df85e6de9\r\nInitial Sample Review\r\nThe initial sample is a relatively large 845KB, which is large for a script based file.\r\nA script-based sample of this size is typically an indicator that there is going to be some heavy obfuscation or junk\r\nto deal with.\r\nAs the file is Javascript and text-based, the next step is to open it in a text editor for further review.\r\nA text editor reveals that the script contains a huge number of junk comments, which is further shown by the mini-map on the right-hand side.\r\nThe style of the junk comments indicates that they were generated from a wordlist, and were likely added by some\r\nform of obfuscator.\r\nhttps://www.embeeresearch.io/latrodectus-script-deobfuscation/\r\nPage 1 of 6\n\nBy leveraging the highlighting provided by visual-studio code, we can scroll through the file to determine if there\r\nis any real functional code.\r\nEvery few hundred lines, there is a small piece of functional javascript containing the actual malware\r\nfunctionality.\r\nCleaning Up the Code and Obtaining Stage 2\r\nAt this stage, we have identified the obfuscation (junk comments) and determined that the file contains real code.\r\nTo deal with this, we can use a regular expression to remove the junk comments by specifying that we want to\r\nremove any line beginning with double forward slashes.\r\nThis regular expression specifies that we want double forward slashes followed by anything followed by a\r\nnewline. We have also added a caret ^ to specify that we only want this at the beginning of a line.\r\nAfter applying the regular expression, we're left with only 37 lines of code, which is significantly shorter than the\r\noriginal 1890.\r\nhttps://www.embeeresearch.io/latrodectus-script-deobfuscation/\r\nPage 2 of 6\n\nHowever, 37 lines of code is still quite short. This gives the impression that there is something more interesting\r\nand tricky to this script.\r\nIf we observe the code more closely, we can see that it is opening and reading its own contents and looking for\r\nany lines that begin with 4 forward slashes.\r\nThis reveals that the \"junk\" comments were not all junk; some of them contained code that formed the next piece\r\nof the malicious script.\r\nIf we return to the original script, we can see that the lines containing four forward slashes contain code.\r\nThe remainder of this stage is responsible for executing the \"comments\" in the original script.\r\nhttps://www.embeeresearch.io/latrodectus-script-deobfuscation/\r\nPage 3 of 6\n\nObtaining Stage 3\r\nAt this point, we know that an additional piece of malware is stored inside the comments of the original script.\r\nLuckily, we know that the malicious portions begin with four forward slashes. Hence, we can use a regular\r\nexpression to isolate these lines of code.\r\nTo obtain this next stage, we can load the original script (with junk comments) into CyberChef and use a regular\r\nexpression to extract the lines beginning with four forward slashes.\r\nWe can also leverage a capture group and \"List capture groups\" to display only the malicious code and avoid\r\ndisplaying the forward slashes.\r\nhttps://www.embeeresearch.io/latrodectus-script-deobfuscation/\r\nPage 4 of 6\n\nReview of Final Script\r\nThe results of the CyberChef operation can be moved into a text editor for final review.\r\nOn line 17 of the new script, we can see that the malware attempts to map to a network drive at\r\nsokingscrosshotel[.]com\r\nOnce the network drive is mapped to a drive letter, the malware connects the drive using the net use command.\r\nOnce the drive is connected, the malware attempts to execute an upd.msi files using msiexec.exe .\r\nhttps://www.embeeresearch.io/latrodectus-script-deobfuscation/\r\nPage 5 of 6\n\nOnce the file is executed, the network drive is removed using RemoveNetworkDrive from the WScript.Network\r\nobject.\r\nDetection Opportunities\r\nThe malware leverages WMI to execute the net.exe and msiexec.exe commands.\r\nThis produces a process tree similar to that below. With the appropriate process creation logs, an analyst could\r\nsearch for wmiprvse.exe spawning net.exe with references to suspicious or unknown drive names.\r\nThe below command would produce a similar pattern. This could be hunted by looking for wmiprvse.exe\r\nspawning msiexec.exe with references to uncommon share names.\r\nSign up for Embee Research\r\nMalware Analysis and Threat Intelligence\r\nNo spam. Unsubscribe anytime.\r\nSource: https://www.embeeresearch.io/latrodectus-script-deobfuscation/\r\nhttps://www.embeeresearch.io/latrodectus-script-deobfuscation/\r\nPage 6 of 6", "extraction_quality": 1, "language": "EN", "sources": [ "Malpedia" ], "references": [ "https://www.embeeresearch.io/latrodectus-script-deobfuscation/" ], "report_names": [ "latrodectus-script-deobfuscation" ], "threat_actors": [], "ts_created_at": 1775434387, "ts_updated_at": 1775791235, "ts_creation_date": 0, "ts_modification_date": 0, "files": { "pdf": "https://archive.orkl.eu/feed7d58eb4e93a05219ed80984b4ec02361c2fd.pdf", "text": "https://archive.orkl.eu/feed7d58eb4e93a05219ed80984b4ec02361c2fd.txt", "img": "https://archive.orkl.eu/feed7d58eb4e93a05219ed80984b4ec02361c2fd.jpg" } }