{"id":"MAL-2026-13088","summary":"Malicious code in boxy-test-block (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (a2ce2597c942a6017ba1aad05cadffba71e6673f8ae9298ef589493e3c4e5ad3)\nOn require('boxy-test-block'), index.js loads _compat.js which reconstructs attacker-controlled destination hosts via string-split obfuscation (oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev, with DNS-TXT chunked fallback via sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru), fetches an opaque platform-specific binary over HTTPS, writes it to /var/tmp/.cache_\u003chex\u003e on Unix or %TEMP%\\dotnet_diag_\u003chex\u003e.exe on Windows, sets mode 0755 via fs['chmod'+'Sync'], and spawns it detached via /bin/sh -c or cmd.exe /c start /b. Dangerous APIs are hidden with concatenation (require('child_'+'process'), fs['chmod'+'Sync']) to evade static scanners. A second dropper implementation using the same toolkit (base64 chunk decoder, HTTPS + DNS-TXT service discovery, chmod 0755, spawn '/bin/sh -c filePath &') is bundled in lib/telemetry.js. The %TEMP%\\dotnet_diag_*.exe and /var/tmp/.cache_* staging names are cover for persistence.\n","modified":"2026-08-05T15:52:18.067630193Z","published":"2026-08-05T14:25:07Z","database_specific":{"malicious-packages-origins":[{"import_time":"2026-08-05T15:19:43.022508439Z","modified_time":"2026-08-05T14:25:07Z","sha256":"a2ce2597c942a6017ba1aad05cadffba71e6673f8ae9298ef589493e3c4e5ad3","source":"amazon-inspector","versions":["35.9.5"],"id":"IN-MAL-2026-015292"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/boxy-test-block/v/35.9.5"}],"affected":[{"package":{"name":"boxy-test-block","ecosystem":"npm","purl":"pkg:npm/boxy-test-block"},"versions":["35.9.5"],"database_specific":{"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"indicators":{"evidence_files":[{"tlsh":"0ea1b79a06b670098b709be0c7275416f65bf6633680d194f7aca9884fb6134c372dfc","path":"_compat.js","sha256":"abbdf8deadbf4be8971891217fc1ecf8eca34ff8abc333f55edbb0118f6611da"},{"sha256":"37b659b5a23286e4528b1a34ea8fa4494c9ed9acda60d458e836aeaffd94beb3","tlsh":"d0835055566a242186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc","path":"lib/telemetry.js"}],"package_integrity":[{"filename":"boxy-test-block-35.9.5.tgz","hashes":{"sha1":"b5c25cb80503f77051fd44f0289f2100dfd1d216","sha512_sri":"sha512-WgL8YG2PxOyqzdd6xpxNGPudH+f8G2hDf1rslzwXIXqqc82779kZRu+XvCGNsmuxPdtNKqJcbHdhgRhnE6ercA=="}}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/boxy-test-block/MAL-2026-13088.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}