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Operation Rewrite: Chinese-Speaking Threat Actors Deploy BadIIS in a Wide Scale SEO Poisoning Campaign

Medium
Published: Thu Sep 25 2025 (09/25/2025, 09:20:57 UTC)
Source: AlienVault OTX General

Description

A Chinese-speaking threat actor group, tracked as CL-UNK-1037, has been conducting a large-scale SEO poisoning campaign called Operation Rewrite. The attackers use a malicious IIS module named BadIIS to intercept and alter web traffic on compromised servers, manipulating search engine results to redirect users to malicious sites. The campaign primarily targets East and Southeast Asia, with a focus on Vietnam. The attackers employ various tools including native IIS modules, ASP.NET handlers, and PHP scripts. The operation shows links to previously known threat groups like Group 9 and possibly DragonRank. The campaign demonstrates sophisticated techniques for search result manipulation and traffic redirection, posing significant risks to unsuspecting internet users.

AI-Powered Analysis

AILast updated: 09/25/2025, 14:20:08 UTC

Technical Analysis

Operation Rewrite is a sophisticated SEO poisoning campaign conducted by a Chinese-speaking threat actor group identified as CL-UNK-1037. The attackers leverage a malicious IIS (Internet Information Services) module named BadIIS to compromise web servers and intercept web traffic. By manipulating HTTP responses and altering search engine results, they redirect users to malicious websites, potentially exposing them to further malware infections, phishing, or fraud. The campaign primarily targets servers in East and Southeast Asia, with a particular focus on Vietnam. The attackers utilize a combination of native IIS modules, ASP.NET handlers, and PHP scripts to maintain persistence and control over compromised systems. The operation shows links to previously known threat groups such as Group 9 and possibly DragonRank, indicating a continuation or evolution of prior SEO poisoning tactics. Techniques employed include web shell deployment, command execution (T1059), exploitation of web server vulnerabilities (T1190), and traffic redirection (T1189). This campaign is notable for its scale and the complexity of its manipulation of search engine results, which can undermine user trust in legitimate websites and search engines. Although no known exploits are currently reported in the wild for this specific BadIIS module, the threat actor’s ability to compromise IIS servers and manipulate web traffic represents a significant risk to organizations hosting web services on Microsoft IIS platforms.

Potential Impact

For European organizations, the direct impact of Operation Rewrite may be limited due to the campaign's current geographic focus on East and Southeast Asia, especially Vietnam. However, European entities running IIS web servers could be at risk if the campaign expands or if similar tactics are adopted by other threat actors targeting Europe. The manipulation of search engine results can lead to reputational damage, loss of user trust, and potential exposure of users to malware or phishing attacks. Compromised IIS servers can also serve as footholds for further network intrusion, data exfiltration, or lateral movement within an organization. Additionally, organizations involved in international business with Asia or hosting multilingual websites could inadvertently become targets or collateral victims. The campaign’s use of native IIS modules and web shells complicates detection and remediation, increasing the risk of prolonged compromise and operational disruption.

Mitigation Recommendations

European organizations should implement targeted measures beyond generic advice: 1) Conduct thorough audits of IIS servers to detect unauthorized modules such as BadIIS or unusual ASP.NET handlers and PHP scripts. 2) Employ advanced web server monitoring tools capable of detecting anomalous traffic interception or manipulation. 3) Harden IIS configurations by disabling unnecessary modules and enforcing strict access controls on web server components. 4) Regularly update and patch IIS and related web application frameworks to close known vulnerabilities that could be exploited for module injection or web shell deployment. 5) Implement network segmentation to limit the impact of compromised web servers and restrict outbound traffic to prevent malicious redirections. 6) Use threat intelligence feeds to monitor for indicators of compromise related to Operation Rewrite and related groups. 7) Educate web administrators on recognizing signs of SEO poisoning and unusual search result behaviors. 8) Deploy web application firewalls (WAFs) with custom rules to detect and block malicious IIS module activity and traffic redirection attempts.

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Technical Details

Author
AlienVault
Tlp
white
References
["https://unit42.paloaltonetworks.com/operation-rewrite-seo-poisoning-campaign"]
Adversary
CL-UNK-1037
Pulse Id
68d50979e4d5d3cea426e8e4
Threat Score
null

Indicators of Compromise

Url

ValueDescriptionCopy
urlhttp://404.300bt.com/zz/u.php
urlhttp://404.008php.com/
urlhttp://404.008php.com/zz/u.php
urlhttp://404.300bt.com/index.php
urlhttp://404.hao563.com/index.php
urlhttp://404.hao563.com/zz/u.php
urlhttp://404.hzyzn.com/index.php
urlhttp://404.hzyzn.com/zz/u.php
urlhttp://404.pyhycy.com/index.php
urlhttp://404.pyhycy.com/zz/u.php
urlhttp://404.yyphw.com/index.php
urlhttp://404.yyphw.com/zz/u.php
urlhttp://cs.pyhycy.com/index.php
urlhttp://cs.pyhycy.com/zz/u.php
urlhttp://vn404.008php.com/index.php
urlhttp://vn404.008php.com/zz/u.php
urlhttp://www.massnetworks.org
urlhttp://x404.008php.com/index.php
urlhttp://x404.008php.com/zz/u.php
urlhttps://fb88s.icu/uu/tt.js
urlhttps://sl.008php.com/kt.html

Hash

ValueDescriptionCopy
hash0721efb9a3e364a372bbb4b7b7c42193
hash1b899dac682ebb923dc000197f6a203c
hash5ed7d3f4e83c9456363c0502a7b00fac
hash5ee8c01ebebcef28e4e43b20635cd7f1
hash6049f6d24d84b335ae8eb19d049e9e42
hash6cada79fd399172f4ff55774ad1954ce
hash71671fa8ac26d056939f44ed4737663e
hash728605f7586642a814e900e9b2f236fb
hash74863e35f68f27386eb0f65528b5855a
hash8bebaea0998d61e4e0a0ec4201530942
hash920a193888df5adef270d3f05e907d8b
hash941cf0549f9246c655e77767cacb8666
hash952961da4854a37c1888ef384c954aa1
hash97a78238ffa97e140d05d18611979d55
hasha1212cf64c21ac1d08e739e7a28a4279
hashb1760f43574b88382fcdc589ca458254
hashc2cb729cd35c30d3ebcdc8b79abdd482
hashc2fdcb3f36a2c28375f655781acdcf5e
hashc4ea753b0a18b63a46fad031654f9160
hashd6b2516e12b119fec38b89e749848015
hashd9dfffd7dabd24728c9220fe63a42ab0
hashdb3652d42598323481d3168409b5b9bb
hashe50a3e8071e49e17d4d11e98e57cddc8
hashe7e8240be190f80c52fd4c8f26f61f68
hasheb84dc41215111343b0336c92715cbe5
hashebe4e97053230d841d9f5fca62caf9ac
hashf080c768e57727f0f60d89f74e1c6131
hashf413647083a0701e91b5a2fc247fd586
hash0285093143f00f2e3d37f8ce3cf8a4c26c2de38b
hash11ce546e53b9a126fde2cfe83bd2d989ecba5d1f
hash1634be0effa407a3bad9566eb1401ba221cd0a25
hash166c65fa8a74f6baf2d5ccd7380b98842bd740f1
hash182e53917e6b25bc2ed4c819bdd8fb559bd7a9fb
hash1905357c256088a2a906ad6ad3591c54562a0960
hash1cdc83af81a2dd50c5edaf81024583a30fecb416
hash290154cbd437fb58972b00676c024db953db226c
hash2cf2037eba59bf894959c051e9cfbe8d7dc5945d
hash3070be0077c62d7be7207f4680ba4fffa5c35e24
hash3e5d55a4e8a10967478f32224da252e897fa3cf9
hash3ed2b0d2289a91d1e39726b96ff268b65e275767
hash449ada079dcabfb41c9078e4e4e246b975493534
hash44c17b311c08f72563513946ff7db640f1af4ecb
hash4f6be5fe8d87a3ed61440b40682616b74cb0071e
hash6dff956e68de3f1728421a043861dd794c2fcd33
hash798db0dda596904adf3a34d1e6c322b441f324cc
hash84281ad4e1c2f6523704800b10fee46ce18aeb09
hash89f63ed2abc9507c0f4362adfc7c2272119ad99d
hashb941f250479023698a3e6987fab710101d077239
hashbdde78f432db8f2d4eecdcb9039ea32c9e5380f0
hashc139b3ee899b235877fcea5f4579f222ef730141
hashc4ed03a02b3f61a71cd9b2f8cc0e84433d776342
hashd89eebb3640185691773c06cd925076d7e726b10
hashdf145c5ec3447bb14b14aaf5aa5d872d12390c9a
hashe336988626311997cea16d3b54c4ccbdf106ebfb
hashef074157dd833654e16abfb1a6967265aeb440e1
hashf629f1ea613e9cda2949b962e979d0197b3c2665
hash01a616e25f1ac661a7a9c244fd31736188ceb5fce8c1a5738e807fdbef70fd60
hash1c870ee30042b1f6387cda8527c2a9cf6791195e63c5126d786f807239bd0ddc
hash22a4f8aead6aef38b0dc26461813499c19c6d9165d375f85fb872cd7d9eba5f9
hash22a9e1675bd8b8d64516bd4be1f07754c8f4ad6c59a965d0e009cbeaca6147a7
hash23aa7c29d1370d31f2631abd7df4c260b85227a433ab3c7d77e8f2d87589948f
hash271c1ddfdfb6ba82c133d1e0aac3981b2c399f16578fcf706f5e332703864656
hash2af61e5acc4ca390d3bd43bc649ab30951ed7b4e36d58a05f5003d92fde5e9a7
hash36bf18c3edd773072d412f4681fb25b1512d0d8a00aac36514cd6c48d80be71b
hash40a0d0ee76b72202b63301a64c948acb3a4da8bac4671c7b7014a6f1e7841bd2
hash5aa684e90dd0b85f41383efe89dddb2d43ecbdaf9c1d52c40a2fdf037fb40138
hash6cff06789bf27407aa420e73123d4892a8f15cae9885ff88749fd21aa6d0e8ad
hash6d044b27cd3418bf949b3db131286c8f877a56d08c3bbb0924baf862a6d13b27
hash6d79b32927bac8020d25aa326ddf44e7d78600714beacd473238cc0d9b5d1ccf
hash78ef67ec600045b7deb8b8ac747845119262bea1d51b2332469b1f769fb0b67d
hash8078fa156f5ab8be073ad3f616a2302f719713aac0f62599916c5084dd326060
hash82096c2716a4de687b3a09b638e39cc7c12959bf380610d5f8f9ac9cddab64d7
hash88de33754e96cfa883d737aea7231666c4e6d058e591ef3b566f5c13a88c0b56
hasha393b62df62f10c5c16dd98248ee14ca92982e7ac54cb3e1c83124c3623c8c43
hasha73c7f833a83025936c52a8f217c9793072d91346bb321552f3214efdeef59eb
hashab0b548931e3e07d466ae8598ca9cd8b10409ab23d471a7124e2e67706a314e8
hashb056197f093cd036fa509609d80ece307864806f52ab962901939b45718c18a8
hashb95a1619d1ca37d652599b0b0a6188174c71147e9dc7fb4253959bd64c4c1e9f
hashbc3bba91572379e81919b9e4d2cbe3b0aa658a97af116e2385b99b610c22c08c
hashc5455c43f6a295392cf7db66c68f8c725029f88e089ed01e3de858a114f0764f
hashc6622e2900b8112e8157f923e9fcbd48889717adfe1104e07eb253f2e90d2c6a
hashd6a0763f6ef19def8a248c875fd4a5ea914737e3914641ef343fe1e51b04f858
hashd8a7320e2056daf3ef4d479ff1bb5ce4facda67dfc705e8729aeca78d6f9ca84
hashde570369194da3808ab3c3de8fb7ba2aac1cc67680ebdc75348b309e9a290d37
hashe2e00fd57d177e4c90c1e6a973cae488782f73378224f54cf1284d69a88b6805
hashed68c5a8c937cd55406c152ae4a2780bf39647f8724029f04e1dce136eb358ea

Ip

ValueDescriptionCopy
ip103.6.235.26
ip103.6.235.78
ip160.30.173.87

Domain

ValueDescriptionCopy
domain008php.com
domainfb88s.icu
domain404.008php.com
domain404.300bt.com
domain404.hao563.com
domain404.hzyzn.com
domain404.pyhycy.com
domain404.yyphw.com
domaincs.pyhycy.com
domainfcp.yyphw.com
domainqp.008php.com
domainsc.300bt.com
domainsl.008php.com
domainvn404.008php.com
domainwww.massnetworks.org
domainwww.victim.com
domainx404.008php.com

Threat ID: 68d54f4fee8591765f469634

Added to database: 9/25/2025, 2:18:55 PM

Last enriched: 9/25/2025, 2:20:08 PM

Last updated: 9/25/2025, 10:44:53 PM

Views: 8

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