{
	"id": "c9866566-be02-414b-999c-91bd1de9b7f5",
	"created_at": "2026-04-06T00:15:24.033339Z",
	"updated_at": "2026-04-10T03:24:23.729298Z",
	"deleted_at": null,
	"sha1_hash": "84690c194d005f3c514cff2b8536e8ed6defaf36",
	"title": "Nitrogen Dropping Cobalt Strike – A Combination of “Chemical Elements”",
	"llm_title": "",
	"authors": "",
	"file_creation_date": "0001-01-01T00:00:00Z",
	"file_modification_date": "0001-01-01T00:00:00Z",
	"file_size": 4000236,
	"plain_text": "Nitrogen Dropping Cobalt Strike – A Combination of “Chemical\r\nElements”\r\nBy Maurice Fielenbach\r\nPublished: 2026-03-30 · Archived: 2026-04-05 17:47:44 UTC\r\nFirst detected in September 2024 and initially targeting the United States and Canada, the Nitrogen ransomware\r\ngroup has since expanded its reach into parts of Africa and Europe. Many of their victims remain absent from\r\nNitrogen’s public ransomware blog and likely never will be listed. At the time of writing, ransomware.live reports\r\n21 known victims of Nitrogen. Notably, indicators of this malware family surfaced as early as 2023, suggesting\r\nlinks to other ransomware infections.\r\nIn this post, we’ll share details from a recent, non-published, Nitrogen ransomware case, including how the\r\nattackers gained initial access, their lateral movement across systems (confirmed through user access logs), and\r\nhow they attempted to cover their tracks by clearing logs. By examining Windows Error Reporting (WER) and\r\ncrash dump files, we uncovered a Cobalt Strike configuration, along with a Cobalt Strike C2 team server and the\r\nattacker’s use of a pivot system.\r\nMalvertising to Gain Initial Access\r\nIn recent months, threat actors have leveraged targeted Nitrogen-themed malvertising, bundling malicious code\r\nwithin tools that appear legitimate. For instance, thedfirreport documented a Nitrogen campaign that distributed a\r\nfake “Advanced IP Scanner,” ultimately leading to a BlackCat ransomware infection. Similar malvertising tactics\r\nhave been observed with disguised versions of FileZilla and WinRAR.\r\nDuring one of our recent investigations, a user searching for “WinSCP download” via Microsoft Edge clicked on a\r\nsuspicious ad served through Bing. The ad redirected them from ftp-winscp[.]org to a compromised\r\nWordPress site hosting a malicious WinSCP ZIP file — establishing the initial foothold (“beachhead”) in a\r\nbroader attack chain.\r\nWinSCP ZIP download detected in Microsoft Edge browser history on patient zero\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 1 of 20\n\nWithin the ZIP archive, WinSCP-6.3.6-Setup.zip (SHA-256:\r\nfa3eca4d53a1b7c4cfcd14f642ed5f8a8a864f56a8a47acbf5cf11a6c5d2afa2 ), several files were bundled: a\r\nmalicious python312.dll , three legitimate DLLs, and a renamed python.exe labeled setup.exe . Once the\r\nuser ran setup.exe , DLL sideloading occurred — WinSCP was installed in the foreground while the malicious\r\nDLL was loaded into the running process.\r\nMalicious WinSCP ZIP bundled files\r\nAs indicated by the imports in setup.exe, python312.dll is invoked as a dependency at runtime, triggering the\r\nexecution of the malicious DLL. Because the file path for the DLL is not defined with an absolute file path in\r\nsetup.exe, Windows relies on its default DLL search order: it first checks the application’s directory, then the\r\nsystem directory, the Windows directory, and finally the PATH environment variable if the DLL is still not found.\r\nsetup.exe imports\r\nCloser inspection of the malicious DLL, also referenced as the “NitrogenLoader,” shows that it mirrors the same\r\nexports and ordinals found in a genuine Python DLL. For example, it includes the Py_Main export mentioned in\r\nthe setup.exe import table. However, whereas a legitimate python312.dll (for instance,\r\n278f22e258688a2afc1b6ac9f3aba61be0131b0de743c74db1607a7b6b934043 ) features authentic logic, the malicious\r\nfile uses a minimalist approach, returning null instructions instead.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 2 of 20\n\nComparison of a legitimate and malicious python312.dll\r\nIts primary malicious backdoor functionality resides in the DllMain export, in which the packed connect-back\r\nlogic establishes a C2 connection. Various forensic artifacts — including Prefetch files on the compromised\r\nWindows client — confirmed that setup.exe and, consequently, python312.dll executed successfully,\r\nultimately compromising Patient Zero.\r\nWindows Host Triaging\r\nTypically, when analyzing a system — unless you’re performing a scheduled compromise assessment — you have\r\nsome lead pointing you toward the right direction for your forensic investigation. Doing forensics without a clear\r\nlead or well-defined questions is like setting off on vacation without deciding where you want to go. With that in\r\nmind, we rely on a battle-tested workflow to analyze systems and determine which tools to run, a process we refer\r\nto as “preparational forensics”. It’s partially automated, so we don’t have to deploy the same tools every time\r\nmanually. As usual, we started off by analyzing “patient zero” with Velociraptor’s triage output.\r\nAfter confirming infection, we took a full disk image. We won’t go into every detail of our standard deep-dive\r\nworkflow here, but one key step we always take is to run THOR and look for recently created executables in the\r\nMaster File Table. We focused on executables created that same day because we knew the exact timestamp of the\r\nWinSCP infection and suspected the threat actor might have used a C2 framework like Cobalt Strike. This\r\napproach led us to files named Intel64.exe , tcpp.exe , and IntelGup.exe .\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 3 of 20\n\nNewly created executables on patient zero\r\nAs mentioned before, it’s also possible to run THOR against a system image, or, as we did, a mounted disk image\r\nby running thor64.exe --lab -p F:\\ --htmlfile A:\\Artifacts\\case\\output.html , where the F:\\ drive\r\nserved as the mount point.\r\nAnother option is to aim THOR directly at specific files of interest created on the day of initial infection, which, in\r\nthis case, flagged tcpp.exe as containing a potential Cobalt Strike configuration. A byte pattern in this specific\r\nfile that stood out was the recurring value 0x2e , a default XOR key for encrypting configurations in many\r\nversions of Cobalt Strike. Whenever we see stretches of 0x2e or 0x69 in a file, it usually indicates XOR-encrypted null bytes.\r\nTHOR detection highlighting a potential Cobalt Strike byte pattern\r\nSeveral methods can help reveal more details about this potential Cobalt Strike configuration. The one we\r\ntypically use is to copy the suspicious byte section and decrypt it using CyberChef or Python. From there, we can\r\nexport the decrypted data and feed it into a Cobalt Strike parser.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 4 of 20\n\nPotential encrypted Cobalt Strike configuration pattern\r\nThe first step is to copy the 0x2e pattern, paste it into CyberChef, and decrypt it using 0x2e . Straight away, you\r\ncan see interesting strings appearing.\r\nCobalt Strike decryption using CyberChef\r\nNext, we can download the decrypted blob and leverage Sentinel One’s CobaltStrikeParser, extracting and parsing\r\neven more information.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 5 of 20\n\nCobalt Strike configuration detection using CobaltStrikeParser\r\nA particularly noteworthy aspect of the detected Cobalt Strike configuration was its reference to the internal IP\r\naddress 192.168.101.XXX on port 5000 , which happened to match patient zero’s own IP. This detail strongly\r\nsuggests that patient zero was being used as a pivot for a Cobalt Strike beacon — a conclusion that became even\r\nclearer later in our investigation. We also observed that gpupdate.exe was employed as a sacrificial process for\r\nCobalt Strike, as post-compromise payloads are typically injected into dedicated processes.\r\nNote: The manual process described above for extracting Cobalt Strike configurations using the 0x2e\r\npattern will soon be obsolete. THOR v11 includes a built-in feature that automatically detects, decrypts,\r\nand parses Cobalt Strike Beacon configurations — directly during the scan, no manual steps required.\r\nThis feature will be covered in more detail in an upcoming blog post.\r\nInterjection – Cobalt Strike Detection and Threat Intel\r\nFrom these strings — for example, @%windir%\\syswow64\\gpupdate.exe, @%windir%\\sysnative\\gpupdate.exe ,\r\nand the watermark hash S+sMUHERQLpRZukekGExAw== — we can build a custom YARA rule. Encrypting each of\r\nthese strings with all possible single-byte values makes it possible to detect additional XOR-encrypted Cobalt\r\nStrike configurations, not only on patient zero but also on other potentially compromised hosts.\r\n#!/usr/bin/env python3\r\ndef main():\r\n results = []\r\n str_input = [\"@%windir%\\syswow64\\gpupdate.exe\", \"@%windir%\\sysnative\\gpupdate.exe\", \"S+sMUHERQLpR\r\n for string in str_input:\r\n for key in range(256): # 0x00 through 0xFF\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 6 of 20\n\nxored_bytes = [ord(ch) ^ key for ch in string] # XOR each character\r\n xored_hex = \"\".join(f\"{byte:02x}\" for byte in xored_bytes)\r\n results.append((key, xored_hex))\r\n # Write results to file\r\n with open(\"output.txt\", \"w\", encoding=\"utf-8\") as f:\r\n i = 0\r\n for key, xored_str in results:\r\n f.write(f\"$s{i} = \\\"{xored_str}\\\"\\n\")\r\n i += 1\r\n print(\"All XOR variations written to output.txt\")\r\nif __name__ == \"__main__\":\r\n main()\r\nUsing the script’s output, we can create a very simple YARA rule to be used during the engagement, potentially\r\nhighlighting even more suspicious files like the one we already discovered.\r\nYARA Cobalt Strike signature and rule creation\r\nNotably, the identified Cobalt Strike watermark 678358251 has previously been listed on abuse.ch. This\r\nwatermark has been associated with multiple threat actors, including the ransomware group Black Basta, further\r\nhighlighting its reuse across malicious campaigns and threat actors. Cobalt Strike watermarks serve as unique\r\nidentifiers, allowing to track and correlate activity across disparate Cobalt Strike C2 servers observed in the wild.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 7 of 20\n\nCobalt Strike C2 team servers with watermark 678358251\r\nDetecting Lateral Movement with User Access Logging\r\nAfter identifying patient zero, we set out to locate further compromised hosts. Tracking lateral movement from\r\npatient zero proved challenging because artifacts on the source system are typically less thorough than those on\r\nthe destination. Complicating matters even more, the threat actor had cleared critical Windows event logs —\r\namong them the Security, System, and PowerShell logs — on several machines, as shown in the following\r\nscreenshot.\r\nLog clearing detected using Hayabusa\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 8 of 20\n\nNevertheless, not all forensic data was lost. Even with extensive log clearing, we built a supertimeline on one of\r\nthe client’s physical Windows servers, revealing User Access Logging (UAL) entries. These entries provided clear\r\nevidence of lateral movement to another Windows Server originating from the beachhead on the exact date of the\r\ninitial compromise.\r\nUser access logging artifacts in a system supertimeline\r\nBasic Crash Dump Triaging\r\nWhen we reran THOR against the newly uncovered compromised server system, it yielded some additional leads.\r\nIn this instance, we discovered a suspicious operating system svchost.exe file that presented telltale signs of\r\nCobalt Strike activity.\r\nTHOR detection of Cobalt Strike artifacts in a user mode crash dump\r\nWe also found that a Windows Error Reporting (WER) log for this particular svchost.exe was saved in\r\nC:\\ProgramData\\Microsoft\\Windows\\WER . WER is a highly underrated artifact capable of capturing detailed\r\ndebug information, such as the application name, loaded modules, and a heap dump that preserves the memory\r\ndata active at the time of a crash. If configured to do so, WER also collects user-mode crash dumps and stores\r\nthem locally whenever an application crashes — exactly the situation THOR detected here. Although crash dumps\r\nare disabled by default, administrators can enable them by configuring the registry key\r\nHKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Windows\\Windows Error Reporting\\LocalDumps .\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 9 of 20\n\nCrash dump SOFTWARE registry hive configuration\r\nIn recent years, these crash dumps have improved considerably and can be analyzed in more depth using tools like\r\nWinDBG — a process we’ll explore in the next chapter. In this specific scenario, we verified the crash dump\r\nsettings by reviewing the registry keys and confirmed that a full dump (dump type 2), which includes all virtual\r\nmemory, was being saved to the %LOCALAPPDATA%\\CrashDumps directory, with a maximum of ten dump files\r\nretained.\r\nFrom the svchost.exe.17872.dmp crash dump we identified through THOR, several suspicious string artifacts\r\npointed to a possible Cobalt Strike beacon configuration. THOR referenced a GitHub repository — “Detects\r\nspecific keywords found in Malleable C2 profiles for Office 365 Calendar” — indicating that both client and\r\nserver configuration details, including cookie header values from the client and custom headers from the server,\r\nhad been embedded within the crash dump.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 10 of 20\n\nM365 Calendar Profile on GitHub\r\nTo confirm these findings, we used bstrings.exe to extract strings from the crash dump running bstrings.exe\r\n-f .\\svchost.exe.17872.dmp \u003e .\\svchost.exe.17872.dmp.strings.txt . This process uncovered the precise\r\nconfiguration strings highlighted earlier, revealing what appeared to be an entire HTTP response. We even found a\r\nServer header that matched the system responding to the request.\r\nCobalt Strike HTTP Response in the svchost.exe crash dump\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 11 of 20\n\nWe repeated this methodology until no additional pertinent strings emerged, then ran bstrings.exe to focus\r\nspecifically on URLs: bstrings.exe --lr url3986 -f .\\svchost.exe.17872.dmp -q –sa . That step exposed the\r\nCobalt Strike team server, confirming our suspicions regarding an active beacon configuration within the crash\r\ndump.\r\nC2 Team Server detected in URL strings extracted from the detected crash dump\r\nCrash Dump Analysis with WinDBG\r\nIn this scenario, the process crash dump was configured to capture a full user-mode dump that included all virtual\r\nmemory. Having access to a full dump file allowed for a thorough examination of the process at the time it failed.\r\nBy loading the crash dump directly into WinDBG, the debugger halted at the specific exception that caused the\r\ncrash and displayed the associated thread — thread 0x5 with an ID of 0x4c78 — along with a reference to the\r\nfull memory dump type. The debugger also showed the debug session time, which matched the timestamp of the\r\ncrash dump’s creation.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 12 of 20\n\nCrash dump loaded into WinDBG\r\nThe available information showed that a failure occurred while the process executed the kernel32 function\r\nCreateFileA ( 0x4c78 0x5 kernel32!CreateFileA (00007ffd'2ac44960) ). Running !analyze –v initiated the\r\nexception analysis, revealing details about the operating system version, build, CPU registers, and a stack trace,\r\nalongside an error code. Unfortunately, the error code did not yield any additional clues, only indicating that the\r\nexception must have happened before the error handling routine at 00007ffd'12c5ac52\r\nmscorlib_ni!System.Environment.ResourceHelper.GetResourceStringCode+0x252 .\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 13 of 20\n\nWinDBG analyze extension output\r\nTo gather more insights, the MEX extension provided the command !mex.di (or simply !di when using built-in aliases). This command revealed information about the user under whose account the process was running, as\r\nwell as the operating system version, system uptime, and the process ID.\r\nBasic MEX triaging in WinDBG\r\nFurther investigation involved the !peb command, which examined the Process Environment Block (PEB) — a\r\nstructure containing details on loaded modules, command-line arguments, the image file in use, and the window\r\ntitle for the process. In this instance, the PEB indicated that the process path was C:\\StorageReport\\tcpp.exe , a\r\nfile previously identified as a Cobalt Strike pivot beacon that facilitated tunneling through the patient zero system.\r\nWith a Cobalt Strike configuration discovered in memory (as supported by the string analysis), it was apparent\r\nthat malicious activity had been running within this process.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 14 of 20\n\nPivot beacon identified as windows title metadata in the analyzed crash dump\r\nThese same details could have been extracted manually by inspecting the PEB structure without relying on the\r\n!peb extension. Typically, one would locate the PEB address first by referencing the pseudoregister $peb ( dt\r\n@$peb ). In a kernel-mode dump, the command !process -0 0 would also yield the PEB location. With that\r\naddress in hand — in this case, 0x000000b977fe1000 — the relevant data can be read by issuing a command such\r\nas dt _PEB 000000b977fe1000 .\r\n0:005\u003e dt @$peb\r\nSymbol not found at address 000000b977fe1000.\r\n0:005\u003e dt _PEB 000000b977fe1000\r\nole32!_PEB\r\n +0x000 Reserved1 : [2] \"\"\r\n +0x002 BeingDebugged : 0 ''\r\n +0x003 Reserved2 : [1] \"???\"\r\n +0x008 Reserved3 : [2] 0xffffffff`ffffffff Void\r\n +0x018 Ldr : 0x00007ffd`2af203c0 _PEB_LDR_DATA\r\n +0x020 ProcessParameters : 0x000001e4`ef132160 _RTL_USER_PROCESS_PARAMETERS\r\n +0x028 Reserved4 : [3] (null)\r\n +0x040 AtlThunkSListPtr : (null)\r\n +0x048 Reserved5 : (null)\r\n +0x050 Reserved6 : 4\r\n +0x058 Reserved7 : 0x00007ffd`292bf000 Void\r\n +0x060 Reserved8 : 0\r\n +0x064 AtlThunkSListPtr32 : 0\r\n +0x068 Reserved9 : [45] 0x000001e4`eef20000 Void\r\n +0x1d0 Reserved10 : [96] \"\"\r\n +0x230 PostProcessInitRoutine : (null)\r\n +0x238 Reserved11 : [128] \"???\"\r\n +0x2b8 Reserved12 : [1] (null)\r\n +0x2c0 SessionId : 0\r\nIt is in the _PEB_LDR_DATA member that key information regarding loaded modules resides, as documented by\r\nMicrosoft. The InMemoryOrderModuleList field within the _PEB_LDR_DATA structure is a doubly linked list of\r\nloaded modules, so walking this list can provide details on every module.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 15 of 20\n\n0:005\u003e dt _LIST_ENTRY\r\nole32!_LIST_ENTRY\r\n +0x000 Flink : Ptr64 _LIST_ENTRY\r\n +0x008 Blink : Ptr64 _LIST_ENTRY\r\nThis includes the primary image executable (in this instance, svchost.exe ) and subsequent items referenced in\r\nits InMemoryOrderLinks or InLoadOrderLinks fields.\r\nManual PEB iteration\r\nThe first loaded module points to the next one via its InMemoryOrderLinks or InLoadOrderLinks member,\r\nwhich, in this instance, leads to the address 0x000001e4ef132950 . Because that address is also of type\r\n_LIST_ENTRY , the command dt _LDR_DATA_TABLE_ENTRY 0x000001e4ef132950 can reveal details about the next\r\nlink. This manual approach — iterating through the linked list entry by entry — proves especially useful when\r\nyou need to investigate a specific module or structure in greater depth.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 16 of 20\n\nSecond module in the PEB\r\nReturning to the original purpose — gathering conclusive evidence of a Cobalt Strike beacon residing in memory\r\n— analysis continued by examining suspicious strings and testing them against a Cobalt Strike YARA rule by\r\nElastic.\r\nCobalt Strike YARA rule by Elastic\r\nObserved strings were traced to the corresponding memory address within the dump, revealing that all originated\r\nfrom a similar region. Searching for the MZ header indicated the presence of what looked like a loaded binary at\r\nthat location.\r\nWinDBG potential Cobalt Strike string search\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 17 of 20\n\nBy investigating the DOS header ( ntdll!_IMAGE_DOS_HEADER at 000001e4'eef80000 ), one can identify the PE\r\nheader offset ( e_lfanew ), determine the approximate size of the binary ( SizeOfImage ), and theoretically dump\r\nthat data. However, it is important to note that paging can cause portions of memory to be absent from the dump\r\nfile, so the extracted DLL may be incomplete or partially overwritten.\r\n0:005\u003e dt -r ntdll!_IMAGE_DOS_HEADER 000001e4`eef80000\r\n +0x000 e_magic : 0x5a4d\r\n +0x002 e_cblp : 0x90\r\n +0x004 e_cp : 3\r\n […]\r\n +0x028 e_res2 : [10] 0\r\n +0x03c e_lfanew : 0n184\r\n0:005\u003e ? 000001e4`eef80000 + 0n184\r\nEvaluate expression: 2082773401784 = 000001e4`eef800b8\r\n0:005\u003e dt -r _IMAGE_NT_HEADERS 000001e4`eef800b8\r\nole32!_IMAGE_NT_HEADERS\r\n +0x000 Signature : 0x4550\r\n +0x004 FileHeader : _IMAGE_FILE_HEADER\r\n +0x000 Machine : 0x14c\r\n +0x002 NumberOfSections : 2\r\n +0x004 TimeDateStamp : 0\r\n +0x008 PointerToSymbolTable : 0\r\n +0x00c NumberOfSymbols : 0\r\n +0x010 SizeOfOptionalHeader : 0xe0\r\n +0x012 Characteristics : 0x2102\r\n +0x018 OptionalHeader : _IMAGE_OPTIONAL_HEADER\r\n +0x000 Magic : 0x10b\r\n […]\r\n +0x038 SizeOfImage : 0x3000\r\n +0x03c SizeOfHeaders : 0x200\r\n +0x040 CheckSum : 0xc085\r\n +0x044 Subsystem : 2\r\n +0x046 DllCharacteristics : 0x540\r\n +0x048 SizeOfStackReserve : 0x100000\r\n +0x04c SizeOfStackCommit : 0x1000\r\n +0x050 SizeOfHeapReserve : 0x100000\r\n +0x054 SizeOfHeapCommit : 0x1000\r\n +0x058 LoaderFlags : 0\r\n +0x05c NumberOfRvaAndSizes : 0x10\r\n +0x060 DataDirectory : [16] _IMAGE_DATA_DIRECTORY\r\n +0x000 VirtualAddress : 0\r\n +0x004 Size : 0\r\nUsing .writemem in WinDBG with an appropriate address range ( 000001e4'eef80000 L3000 ) attempts to write\r\nthis region to disk. In this case, portions of memory at 000001e4'eef81000 were unreadable, likely due to paging,\r\nand the range did not encompass the exact strings indicative of the beacon configuration.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 18 of 20\n\nMemory sections written to disk using .writemem WinDBG extension\r\nConsequently, additional blocks of memory were dumped around the suspicious strings — for instance, those\r\ncontaining %02d/%02d/%02d %02d:%02d:%02d , %s (admin) , or Content-Length: %d — in an effort to capture\r\nmore complete data. Although this did not yield a fully parsable beacon configuration in this specific instance, the\r\ndiscovered indicators, combined with previous string analysis, further reinforced that a Cobalt Strike payload had\r\nindeed been running within the process at the time of the crash.\r\nDumped memory region containing potential Cobalt Strike strings\r\nSumming Up\r\nThe Nitrogen ransomware group exemplifies a modern, multi-stage intrusion operation that blends social\r\nengineering, evasive malware, and post-exploitation frameworks. By abusing malvertising — often disguising\r\npayloads as legitimate tools like WinSCP, Advanced IP Scanner, or FileZilla — Nitrogen establishes initial access\r\nvia DLL sideloading, with malicious loaders delivering backdoor functionality through NitrogenLoader.\r\nOnce inside the network, Cobalt Strike becomes their tool of choice for lateral movement, command and control,\r\nand post-compromise activity. In our case study, Nitrogen used a compromised host as a pivot system while\r\nsimultaneously wiping critical Windows logs to hinder detection and response efforts.\r\nThroughout this post, we highlighted various ways to detect and extract Cobalt Strike configurations, including\r\npattern analysis, byte-level XOR decryption, and custom YARA rules. In particular, we emphasized the power of\r\ncrash dump analysis — specifically using Windows Error Reporting (WER) artifacts and WinDBG — to uncover\r\nin-memory indicators of Cobalt Strike beacons, configuration strings, and HTTP response structures embedded in\r\ndump files.\r\nWith that being said—stay safe, make use of lesser-known artifacts like WER, crash dumps, and UAL — and\r\nalways read the labels before you install something from an ad.\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 19 of 20\n\nAbout the author:\r\nMaurice Fielenbach\r\nMaurice Fielenbach trains cybersecurity professionals in reverse engineering and malware analysis — his main\r\narea of focus — and digital forensics through his company, Hexastrike Cybersecurity. The company also develops\r\ntools for red and blue teams and publishes technical blog posts covering both offensive and defensive topics. He\r\nalso serves as Head of CERT at r-tec, leading a team of forensic specialists, managing and investigating a wide\r\nrange of security incidents.\r\nSource: https://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nhttps://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/\r\nPage 20 of 20",
	"extraction_quality": 1,
	"language": "EN",
	"sources": [
		"Malpedia"
	],
	"references": [
		"https://www.nextron-systems.com/2025/04/29/nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements/"
	],
	"report_names": [
		"nitrogen-dropping-cobalt-strike-a-combination-of-chemical-elements"
	],
	"threat_actors": [
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