Case Studies on the Effects of Cyber Attacks: Evaluation of Audit Processes and Digital Risk

Abstract

Threats to data security have shifted from physical environments to digital platforms, evolving into cyber threats. Cyber attacks targeting organizations, in particular, can lead to serious consequences that go beyond threatening the security of financial information – potentially driving businesses to bankruptcy. Using a qualitative research method, a total of 15 corporate cybersecurity cases from eight different sectors - including information technology, healthcare, financial services, retail, construction, logistics and transportation, energy, and media and entertainment - were examined. These cases originated primarily from the United States, as well as Denmark, Finland, Australia, the United Kingdom, and South Korea.

Keywords

• cyber attack
• cyber security
• cyber insurance
• internal audit
• independent audit

Siber Saldırıların Etkileri Üzerine Vak’a Analizleri: Denetim Süreçleri ve Dijital Risk Değerlendirmesi

Abstract

Veri güvenliğini tehdit eden unsurlar fiziksel ortamlardan dijital platformlara taşınarak siber tehditler haline gelmiştir. Özellikle kurumlara yönelik siber saldırılar, finansal bilgilerin güvenliğini tehdit etmesinin ötesinde, işletmeleri iflasa kadar sürükleyebilecek ciddi sonuçlar doğurabilmektedir. Bu çalışmada nitel araştırma yöntemi kullanılarak bilişim, sağlık, finansal hizmetler, perakende, inşaat, lojistik ve taşımacılık, enerji ile medya ve eğlence sektörlerini kapsayan toplam 8 farklı sektörden 15 kurumsal siber güvenlik vak’ası incelenmiştir. Bu vak’alar ağırlıklı olarak Amerika Birleşik Devletleri (ABD)’den olmak üzere, Danimarka, Finlandiya, Avustralya, İngiltere, Güney Kore’den seçilmiştir.

Keywords

• siber saldırı
• siber güvenlik
• siber sigorta
• iç denetim
• bağımsız denetim

References

1. Accenture. (2017, 26 Eylül). Cyber crime drains $11.7 million per business annually, up 62 percent in five years: Accenture and Ponemon Institute report. https://newsroom.accenture.com/news/2017/accenture-and-ponemon-institute-report-cyber-crime-drains-11-7-million-per-business-annually-up-62-percent-in-five-years
2. ACSM_ACCRO. (2024, 19 Temmuz). MediSecure concludes investigation into cyber attack. Australian Cyber Security Magazine. https://australiancybersecuritymagazine.com.au/medisecure-concludes-investigation-into-cyber-attack/
3. Akçakanat, Ö., Özdemir, O., & Mazak, M. (2021). İşletmelerde siber güvenlik riskleri ve bilgi teknolojileri denetimi: Bankaların siber güvenlik uygulamalarının incelenmesi. Mehmet Akif Ersoy Üniversitesi Uygulamalı Bilimler Dergisi, 5(2), 246–270. https://doi.org/10.31200/makuubd.978263
4. Akın, S., & Tanç, A. (2022). İşletmelerde bilgi sistemlerinin denetiminde siber güvenlik risklerinin önemi. Erciyes Akademi, 36(2), 707–722. https://doi.org/10.48070/erciyesakademi.1101315
5. Alder, S. (2021, 12 Mart). Multistate settlement resolves 2019 American Medical Collection Agency data breach investigation. The HIPAA Journal. https://www.hipaajournal.com/multistate-settlement-resolves-2019-american-medical-collection-agency-data-breach/
6. Alkan, A. M. (2023). Sigorta sektöründe siber riskler. TOGÜ Turhal Uygulamalı Bilimler Fakültesi Dergisi, 1(1), 41–50. https://izlik.org/JA58FN82PR
7. Altuntaş, E., Kara, E., Soylu, A. B., & Kırkbeşoğlu, E. (2018). Siber sigortalar: Son gelişmeler, uygulamalar ve sorunlar. Bankacılık ve Sigortacılık Araştırmaları, 12, 8–22. https://izlik.org/JA69DJ33ZT
8. Aslay, F. (2017). Siber saldırı yöntemleri ve Türkiye’nin siber güvenlik mevcut durum analizi. International Journal of Multidisciplinary Studies and Innovative Technologies, 1(1), 24–28. https://izlik.org/JA89ET62UE Atakan, M. (2021). Siber güvenlik risklerinin ve COVID-19 salgınının uzaktan denetim üzerindeki etkileri. Denetişim, 22, 27–39. https://izlik.org/JA62ZD72LD

9. Baltacı, A. (2018). Nitel araştırmalarda örnekleme yöntemleri ve örnek hacmi sorunsalı üzerine kavramsal bir inceleme. Bitlis Eren Üniversitesi Sosyal Bilimler Enstitüsü Dergisi, 7(1), 231–274. https://izlik.org/JA98FN96XR BBC. (2017, 19 Aralık). Bitcoin exchange Youbit shuts after second hack attack. https://www.bbc.com/news/technology-42409815
10. Bongiovanni, I., Slapničar, S., Axelsen, M., & Stockdale, D. (2024). The three lines model in cybersecurity governance and risk management. ISACA Journal, 1–6. https://www.isaca.org/resources/isaca-journal/issues/2024/volume-1/the-three-lines-model-in-cybersecurity-governance-and-risk-management
11. Bracewell LLP. (2022, 21 Ocak). Ransomware: An enterprise risk for the unprepared. JD Supra. https://www.jdsupra.com/legalnews/ransomware-an-enterprise-risk-for-the-9058216
12. Capital One. (t.y.). About. https://www.capitalone.com/about/
13. Capital One. (2019). 2019 annual report. https://investor.capitalone.com/static-files/2f0f821a-0db0-4eab-9895-63013c4e59c2
14. Capital One. (2020). 2020 annual report. https://investor.capitalone.com/static-files/1364d634-a3d5-464d-8505-ddf46eda928d
15. Capital One. (2021). 2021 annual report. https://investor.capitalone.com/static-files/20d7fe73-5e16-413f-9167-f8d23eb98885
16. Capital One. (2024). 2024 annual report. https://investor.capitalone.com/static-files/743207f3-f641-40f8-93b5-31f7ae857b41
17. Chin, K. (2025, 5 Ocak). The impact of cybercrime on the economy. UpGuard. https://www.upguard.com/blog/the-impact-of-cybercrime-on-the-economy
18. Cimpanu, C. (2021, 8 Mayıs). SolarWinds says fewer than 100 customers were impacted by supply chain attack. The Record. https://therecord.media/solarwinds-says-fewer-than-100-customers-were-impacted-by-supply-chain-attack
19. CloudDefense.AI. (2014). Codespaces.com data breach. https://www.clouddefense.ai/breaches/2014/codespaces-2014
20. Cohen, A. (2023, 13 Mayıs). Incident report: Knights of Old ransomware attack (2023). SDO Security. https://www.sdosecurity.com/post/incident-report-knights-of-old-ransomware-attack-2023
21. Conformally. (2021). Deputy data protection ombudsman – Psykoterapiakeskus Vastaamo. https://conformally.com/featured_item/deputy-data-protection-ombudsman-psykoterapiakeskus-vastaamo-12-7-2021/
22. CyberPeace Institute. (2020, 28 Ekim). Vastaamo data breach – attack on human security, dignity and equity. https://cyberpeaceinstitute.org/news/2020-10-28-vastaamo-data-breach-attack-on-human-security-dignity-and-equity/
23. Deloitte. (2024). Cyber overview brochure. https://www.deloitte.com/content/dam/assets-shared/docs/services/risk-advisory/2023/deloitte-global-cyber-overview.pdf Dünya Gazetesi. (2025, 10 Mayıs). 2025’te siber saldırıların maliyetinin 10,5 trilyon doları bulması bekleniyor. https://www.dunya.com/ekonomi/2025te-siber-saldirilarin-maliyetinin-105-trilyon-dolari-bulunmasi-bekleniyor-haberi-775858
24. Eroğlu, C. (2023). İşletmelerin maruz kaldığı siber suçların boyutu. Güvenlik Bilimleri Dergisi, 12(1), 69–96. https://doi.org/10.28956/gbd.1264593
25. Ernst & Young (EY). (t.y.). Siber Güvenlik, strateji, risk, uyum ve dayanıklılık. 12 Ağustos 2025 tarihinde https://www.ey.com/tr_tr/services/consulting/cybersecurity-strategy-risk-compliance-resilience adresinden erişildi.
26. Fleck, A. (2024, 22 Şubat). Cybercrime expected to skyrocket in coming years. Statista. https://www.statista.com/chart/28878/expected-cost-of-cybercrime-until-2027/
27. Foltyn, T. (2019, 14 Şubat). Attack at email provider wipes out almost two decades’ worth of data. WeLiveSecurity. https://www.welivesecurity.com/2019/02/14/attack-email-provider-wipes-almost-two-decades-data/
28. Framework Security. (2026, 24 Mart). The Sony Pictures hack: What really happened in 2014. https://www.frameworksec.com/post/the-sony-pictures-breach-a-deep-dive-into-a-landmark-cyber-attack
29. Gatlan, S. (2019, 12 Şubat). Hackers wipe VFEmail servers, may shut down after catastrophic data loss. BleepingComputer. https://www.bleepingcomputer.com/news/security/hackers-wipe-vfemail-servers-may-shut-down-after-catastrophic-data-loss/
30. Gelişim Haber. (2022, 22 Haziran). Siber saldırılarda en zayıf halka şirket kullanıcıları. https://gelisim.edu.tr/tr/gelisim-haber-siber-saldirilarda-en-zayif-halka-sirket-kullanicilari
31. Ghanbari, H., & Koskinen, K. (2024). When data breach hits a psychotherapy clinic: The Vastaamo case. Journal of Information Technology Teaching Cases, 1–9. https://doi.org/10.1177/20438869241258235
32. Greenberg, A. (2014, 19 Haziran). Code Spaces shuts down following DDoS extortion, deletion of sensitive data. SC Media. https://www.scworld.com/news/code-spaces-shuts-down-following-ddos-extortion-deletion-of-sensitive-data
33. Guohong, Z., Zhongwei, X., Feng, H., & Zhongyi, X. (2025). The audit committee’s IT expertise and its impact on the disclosure of cybersecurity risk. Research in International Business and Finance,73, 1-18. https://doi.org/10.1016/j.ribaf.2024.102542
34. Güler, A., & Arkın, A. K. (2019). Siber hijyenin sağlanmasında iç denetimin rolü. Denetişim, 19, 17–40.
35. Hecker, J., & Kalpokas, N. (2026). The ultimate guide to qualitative research—Part 2: Handling qualitative data. ATLAS.ti. https://atlasti.com/guides/qualitative-research-guide-part-2/content-analysis
36. INSURICA. (2021). Cyber case study: Colonial Pipeline ransomware attack. https://insurica.com/blog/colonial-pipeline-ransomware-attack/
37. Islam, M. S., Farah, N., & Stafford, T. F. (2018). Factors associated with security/cybersecurity audit by internal audit function. Managerial Auditing Journal, 33(4), 377–409. https://doi.org/10.1108/MAJ-07-2017-1595
38. Kamu Gözetimi, Muhasebe ve Denetim Standartları Kurumu (KGK). (2025). BDS 240: Finansal tabloların bağımsız denetiminde bağımsız denetçinin hileye ilişkin sorumlulukları. https://www.kgk.gov.tr/Portalv2Uploads/files/Duyurular/v2/TDS/TDS_2025_Seti/BDS%20240_2025.pdf
39. Kamu Gözetimi, Muhasebe ve Denetim Standartları Kurumu (KGK). (2025). BDS 250: Finansal tabloların bağımsız denetiminde mevzuatın dikkate alınması. https://www.kgk.gov.tr/Portalv2Uploads/files/Duyurular/v2/TDS/TDS_2025_Seti/BDS%20250_2025.pdf
40. Kamu Gözetimi, Muhasebe ve Denetim Standartları Kurumu (KGK). (2025). BDS 265: İç kontrol eksikliklerinin üst yönetimden sorumlu olanlara ve yönetime bildirilmesi. https://www.kgk.gov.tr/Portalv2Uploads/files/Duyurular/v2/TDS/TDS_2025_Seti/BDS%20265_2025.pdf
41. Kamu Gözetimi, Muhasebe ve Denetim Standartları Kurumu (KGK). (2025). BDS 315: “Önemli yanlışlık” risklerinin belirlenmesi ve değerlendirilmesi. https://www.kgk.gov.tr/Portalv2Uploads/files/Duyurular/v2/TDS/TDS_2025_Seti/BDS%20315_2025.pdf
42. Kamu Gözetimi, Muhasebe ve Denetim Standartları Kurumu (KGK). (2025). BDS 330: Bağımsız denetçinin risk olarak değerlendirilmiş hususlara karşı yapacağı işler. https://www.kgk.gov.tr/Portalv2Uploads/files/Duyurular/v2/TDS/TDS_2025_Seti/BDS%20330_2025.pdf
43. Kamu Gözetimi, Muhasebe ve Denetim Standartları Kurumu (KGK). (2025). BDS 570: İşletmenin sürekliliği. https://www.kgk.gov.tr/Portalv2Uploads/files/Duyurular/v2/TDS/TDS_2025_Seti/BDS%20570_2025.pdf
44. Kamu Gözetimi, Muhasebe ve Denetim Standartları Kurumu (KGK). (2025). BDS 705: Bağımsız denetçi raporunda olumlu görüş dışında bir görüş verilmesi. https://www.kgk.gov.tr/Portalv2Uploads/files/Duyurular/v2/TDS/TDS_2025_Seti/BDS%20705_2025.pdf
45. Kestane, A. (2021). Siber güvenliğin etkinleştirilmesinde sürekli süreç denetimi modeli. Muhasebe Bilim Dünyası Dergisi, 23(4), 773–796. https://doi.org/10.31460/mbdd.884892
46. Kestane, A., & Kurt, G. (2024). Bulut güvenlik denetimi: Bulut siber güvenlik uygulamalarında iç denetim. Ömer Halisdemir Üniversitesi İktisadi ve İdari Bilimler Fakültesi Dergisi, 17(3), 667–690. https://doi.org/10.25287/ohuiibf.1482734
47. Kirk, J. (2022, 16 Eylül). The Ransomware Files, Episode 11: The adult boutique. BankInfoSecurity. https://www.bankinfosecurity.com/interviews/ransomware-files-ep-11-adult-boutique-i-5148
48. Korkmaz, D. (2025, 30 Haziran). AWS üzerindeki iki kriz: Capital One ve Code Spaces olayları. Medium. https://medium.com/@damlak0rkm6z/aws-üzerindeki-i̇ki-kriz-capital-one-ve-code-spaces-olayları-110f7e5eca59
49. KPMG. (2020). Siber güvenlik olgunluk değerlendirmesi. https://assets.kpmg.com/content/dam/kpmg/tr/pdf/2022/02/siber-guvenlik-olgunluk-degerlendirmesi_2022.pdf
50. Kurt, G., & Uçma Uysal, T. (2015). Siber riskler ve COSO iç kontrol bütünleşik çerçevesi. Muhasebe ve Denetime Bakış, 15(46), 1–10.
51. KuveytTürk. (2023, 4 Temmuz). A'dan Z'ye tüm bilinmesi gerekenleriyle IP adresi nedir? https://www.kuveytturk.com.tr/blog/teknoloji/adan-zye-tum-bilinmesi-gerekenleriyle-ip-adresi-nedir
52. Looi, J. C., Allison, S., Bastiampillai, T., Maguire, P. A., Kisely, S., Reutens, S., & Looi, R. C. (2025). Cybersecurity lessons from the Vastaamo psychotherapy data breach for psychiatrists and other mental healthcare providers. Australasian Psychiatry, 33(1), 106–110. https://doi.org/10.1177/10398562241291340
53. MAC adresi. (t.y.). Vikipedi. 16 Temmuz 2025 tarihinde https://tr.wikipedia.org/wiki/MAC_adresi adresinden erişildi.
54. Masoud, N., & Al-Utaibi, G. (2022). The determinants of cybersecurity risk disclosure in firms’ financial reporting: Empirical evidence. Research in Economics, 76(2), 131–140. https://doi.org/10.1016/j.rie.2022.07.001
55. Milliken, M. (2015, 12 Ocak). Insurance to fully cover Sony’s cyber attack, says CEO. Insurance Journal. https://www.insurancejournal.com/news/national/2015/01/12/353835.htm
56. Mimoso, M. (2014, 18 Haziran). Hacker puts hosting service Code Spaces out of business. Threatpost. https://threatpost.com/hacker-puts-hosting-service-code-spaces-out-of-business/106761/
57. Mual, M. (2017, 20 Aralık). South Korean Bitcoin exchange shuts down after second hack attack. The Paypers. https://thepaypers.com/crypto-web3-and-cbdc/news/south-korean-bitcoin-exchange-shuts-down-after-second-hack-attack
58. Naprys, E. (2023, 24 Ağustos). Ransomware encryption devastates CloudNordic, customer data lost. Cybernews. https://cybernews.com/security/ransomware-encryption-devastates-cloudnordic-customer-data-lost/
59. New York State Attorney General. (2021, 11 Mart). Attorney General James holds American Medical Collection Agency responsible for 2019 data breach. https://ag.ny.gov/press-release/2021/attorney-general-james-holds-american-medical-collection-agency-responsible-2019
60. Okul, Ş., Muratoğlu, Ş., Aydın, M. A., & Bilge, H. Ş. (2019). A review on cyber risk management. Acta Infologica, 3(1), 34–45. https://doi.org/10.26650/acin.502589
61. Oladimeji, S., & Kerner, S. M. (2023, 3 Kasım). SolarWinds hack explained: Everything you need to know. TechTarget. https://www.techtarget.com/whatis/feature/SolarWinds-hack-explained-Everything-you-need-to-know
62. Özcan, İ., & Bircan, N. G. (2023). Bağımsız denetim firmalarında bilgi sistemleri risk yönetimi açısından siber denetim. Mali Çözüm, 33(177), 747–771. https://archive.ismmmo.org.tr/docs/malicozum/177malicozum/09.pdf
63. Öztürk, M. S. (2018). Siber saldırılar, siber güvenlik denetimleri ve bütüncül bir denetim modeli önerisi. Muhasebe ve Vergi Uygulamaları Dergisi, (Özel Sayı), 208–232. https://doi.org/10.29067/muvu.340848
64. Petros, L., Drogalas, G., Karagiorgos, A., & Tsikalakis, K. (2020). Internal audit in the digital era: Opportunities, risks and challenges. EuroMed Journal of Business, 15(2), 205–217. https://doi.org/10.1108/EMJB-07-2019-0097
65. PricewaterhouseCoopers (PwC). (2020). Siber güvenlik ve veri koruma hizmetleri [Broşür]. https://www.pwc.com.tr/tr/Hizmetlerimiz/teknoloji/siber-guvenlik-ve-veri-koruma-hizmetleri/siber-guvenlik-ve-veri-koruma-hizmetleri-hizmet-brosuru-web-2020-0216.pdf
66. Ramakrishna, S. (2021, 7 Mayıs). An investigative update of the cyberattack. SolarWinds. https://www.solarwinds.com/blog/an-investigative-update-of-the-cyberattack
67. Seals, T. (2019, 12 Şubat). Attackers completely destroy VFEmail’s secure mail infrastructure. Threatpost. https://threatpost.com/attackers-completely-destroy-vfemails-secure-mail-infrastructure/141748/
68. Selimoğlu, S., & Altunel, M. (2019). Siber güvenlik risklerinden korunmada köprü ve katalizör olarak iç denetim. Denetişim, 19, 5–16.
69. Selimoğlu, S., & Saldı, M. H. (2019). İşletmelerde siber risklerin analizinde, haritalandırılmasında ve değerlendirilmesinde iç denetimin rolü. Muhasebe ve Denetime Bakış, 57, 1–18.
70. Selimoğlu, S., & Saldı, M. H. (2022). İç denetimin blok zincir yoluyla siber güvenlik yönetimine adaptasyonu. Denetim ve Güvence Hizmetleri, 2(2), 121–134.
71. SolarWinds. (2025a). Company overview. 16 Temmuz 2025 tarihinde https://www.solarwinds.com/company adresinden erişildi.
72. SolarWinds. (2025b). Public sector powered by SolarWinds. 16 Temmuz 2025 tarihinde https://www.solarwinds.com/public-sector/it-management-solutions-for-government adresinden erişildi.
73. SolarWinds Corporation. (2020). Annual report (Form 10-K). https://annual-statements.com/company/solarwinds-corp/annual-report-2020-form-10k-75708
74. SolarWinds Corporation. (2022). Annual report (Form 10-K). https://www.sec.gov/Archives/edgar/data/1739942/000173994223000019/swi-20221231.htm
75. Sonkar, N., Verma, N., Kumar, A., Naqvi, D., & Nisa, Z. (2025). An empirical study on the economic impact of cybersecurity breaches and computer fraud on SMEs. Journal of Information Systems Engineering and Management, 10(7s), 730–735. https://doi.org/10.52783/jisem.v10i7s.986
76. Sony Corporation. (2014). Consolidated financial results. https://www.sony.com/en/SonyInfo/IR/library/presen/er/14q4_sonypre.pdf
77. Sony Corporation. (2015). SEC Form 20-F. https://www.sec.gov/Archives/edgar/data/313838/000119312515231346/d895998d20f.htm
78. Spectrum News 1. (2018, 22 Ekim). Austin software company SolarWinds goes public on NYSE. https://spectrumnews1.com/oh/cincinnati/stories/2018/10/22/austin-software-company-solarwinds-goes-public-on-nyse
79. STM Cyber. (2022). Siber tehdit durum raporu (Ekim–Aralık 2022). https://thinktech.stm.com.tr/tr/siber-tehdit-durum-raporu-ekim-aralik-2022
80. Sunde, S. J. (2017). Assurance and cyber risk management. A. Domenic (Ed.), The cyber risk handbook: Creating and measuring effective cybersecurity capabilities içinde. John Wiley & Sons.
81. Target Corporation. (2013). Annual report. https://dn721901.ca.archive.org/0/items/01-target-archive/2013%20%20-%20Target%20Corp%20(TGT).pdf
82. Target Corporation. (2014). Annual report. https://dn721901.ca.archive.org/0/items/01-target-archive/2014%20-%20Target%20Corp%20(TGT).pdf
83. Target Corporation. (2015). Annual report. https://corporate.target.com/getmedia/e503afc7-58e1-468c-8ff2-8442b3a4a699/Target-2015-Annual-Report.pdf
84. Taylor, J. (2024, 17 Mayıs). MediSecure data breach: Cyber security chief says no current prescriptions affected. The Guardian. https://www.theguardian.com/australia-news/article/2024/may/17/medisecure-data-breach-australia-healthcare-prescriptions-impact
85. Tidy, J. (2024, 30 Nisan). Hacker jailed for blackmailing therapy patients. BBC News. https://www.bbc.com/news/articles/c97znd00q7mo
86. Travelex. (t.y.-a). About us. 5 Temmuz 2025 tarihinde https://www.travelex.co.uk/about-us adresinden erişildi.
87. Travelex. (t.y.-b). Hakkımızda. 5 Temmuz 2025 tarihinde https://www.travelex.com.tr/hakk%C4%B1m%C4%B1zda adresinden erişildi.
88. Travelex, News. (2020). Travelex knocked offline by malware. Computer Fraud & Security, (1). https://doi.org/10.1016/S1361-3723(20)30003-8
89. Travelex Topco Limited. (2021). Financial statements for the year ended 31 December 2021. https://www.travelex-corporate.com/media/7400/travelex-group-financial-statements-2021.pdf
90. Travelex Topco Limited, Director’s Report. (2020). Travelex Topco Limited, Report and consolidated financial statements for the period ended 31 December 2020, https://www.travelex-corporate.com/media/7225/travelex-group-financial-statements-2020-signed-pdf.pdf
91. Travelex Topco Limited, Independent Auditor’s Report. (2020). Travelex Topco Limited, Report and consolidated financial statements for the period ended 31 December 2020, https://www.travelex-corporate.com/media/7225/travelex-group-financial-statements-2020-signed-pdf.pdf
92. Tutar, H. (2023). Nitel araştırma deseni belirleme ölçütleri ve gerekçelendirilmesi. Kastamonu İktisadi ve İdari Bilimler Fakültesi Dergisi, 25(1), 334–355. https://doi.org/10.21180/iibfdkastamonu.1190123
93. Türedi, S. (2012). İç kontrol sistemi ve toplam kalite yönetimi ilişkisi. Uluslararası Alanya İşletme Fakültesi Dergisi, 4(1), 27–37.
94. Tyson, M. (2025, 22 Temmuz). 158-year-old company forced to close after ransomware attack precipitated by a single guessed password – 700 jobs lost after hackers demand unpayable sum. Tom’s Hardware. https://www.tomshardware.com/tech-industry/cyber-security/158-year-old-company-forced-to-close-after-ransomware-attack-precipitated-by-a-single-guessed-password-700-jobs-lost-after-hackers-demand-unpayable-sum
95. Umut, İ. E., & Özer, Ö. (2022). Kripto varlıkların denetimi: Blok zincir teknolojisinin bağımsız denetim sürecine etkisi. Selçuk Üniversitesi Sosyal Bilimler Meslek Yüksekokulu Dergisi, 25(25. yıl özel sayısı), 536–552.
96. UK Department for Science, Innovation and Technology. (2024). Cyber security breaches survey 2024. https://www.gov.uk/government/statistics/cyber-security-breaches-survey-2024/cyber-security-breaches-survey-2024
97. U.S. Securities and Exchange Commission. (2023, 30 Ekim). SEC charges SolarWinds and chief information security officer with fraud, internal control failures. https://www.sec.gov/newsroom/press-releases/2023-227
98. VFEmail. (t.y.). Home page. 8 Temmuz 2025 tarhinde https://vfemail.net/ adresinden erişildi.
99. VPN nedir, ne demek? VPN ne işe yarar? (2024, 2 Ağustos). Hürriyet. https://www.hurriyet.com.tr/bilgi/vpn-nedir-ne-demek-vpn-ne-ise-yarar-42497994
100. Yel, T., & Atasoy, A. (2021). Dijitalleşmenin bağımsız denetime yansımalarının siber güvenlik yönünden değerlendirilmesi, Muhasebe ve Finansman Dergisi, Özel Sayı, 439-458.