## 2 Theoretical Background
### Hypothesis Development  
Existing knowledge of phishing attacks allows the prediction of design features of phishing emails and which personality characteristics of the victims who receive them influence victims' likelihood of responding to these emails and hence become susceptible to phishing attacks. Unfortunately, the same cannot be said for cyber sextortion attacks. Due to the fact that sextortion attacks have been dramatically understudied, little is known about what influences victims' susceptibility to them. Using the email cues identified in the IIPM as influencing susceptibility to phishing attacks (email source, grammar and spelling, urgency cues, and title/subject line) psychological and cybersecurity theories and techniques to investigate this phenomenon are applied to pave the way for future research and an understanding for how these attacks can be effectively mitigated. The aim of this study is to extend our understanding of cyber sextortion by using our current knowledge of the research literature surrounding social engineering attack-based techniques such as phishing to investigate the effects of message-related factors on cyber security behavior and susceptibility to cyber sextortion attacks. Hence, the following hypotheses will be tested. A diagram of the study's hypotheses is presented in Figure 2, showing how paying attention to each design cue within sextortion emails is expected to influence the likelihood of responding to these emails, and hence of influencing susceptibility to cyber sextortion attacks. Hypothesis one: Research has shown that people who focus attention on the email source of phishing emails are more likely to assess the email as inauthentic, reducing the likelihood of responding to it [25]. Therefore, hypothesis one is that focusing attention on the email source (reply-to address) in cyber sextortion emails will correlate with participants rating the email as less likely to be responded to than not focusing attention on the email source (reply-to address). Hypothesis two: Research has shown that individuals who attend to the spelling and grammar within the context of phishing attacks are more likely to assess the email  
Figure 2: The hypothesized relationship between the attention given to various design cues within sextortion emails; and their effects on participants’ likelihood of responding to these emails, and hence being vulnerable to sextortion attacks. as inauthentic, reducing the likelihood of responding to it [26]. Therefore, hypothesis two is that focusing attention on grammar and spelling in cyber sextortion emails will correlate with participants rating the email as less likely to be responded to than not focusing attention on grammar and spelling. Hypothesis three: Research has shown that individuals who attend to the title or subject of the email within the context of phishing attacks are more likely to respond to it, increasing susceptibility [26]. Therefore, hypothesis three is that focusing attention on the title/subject line in cyber sextortion emails will correlate with participants rating the email as more likely to be responded to than not focusing attention on the title/subject line. Hypothesis four: Research has shown that individuals who attend to urgency cues within the context of phishing attacks are more likely to respond to them, increasing susceptibility [26]. Therefore, hypothesis four is that focusing attention on urgency cues in cyber sextortion emails will correlate with participants rating the email as more likely to be responded to than not focusing attention on urgency cues. Hypothesis five: Poor email and security habits have been shown to increase individuals' vulnerability to cyber-attacks [26]. Therefore, hypothesis five is focused on participants' general email habits, security email habits, and attentional email habits correlating with their level of susceptibility to each of the email design cues.