A Survey on the Evolution of Bootkits Attack and Defense Techniques

According to the boot process of modern computer systems,whoever boots first will gain control first.Taking advantage of this feature,a malicious code called bootkit can hijack the control before the OS bootloader and bypass security mechanisms in boot process.That makes bootkits difficult to detect or clean up thoroughly.With the improvement of security mechanisms and the emergence of UEFI,the attack and defense techniques for bootkits have constantly been evolving.We first introduce two boot modes of modern computer systems and present an attack model of bootkits by some sophistical samples.Then we discuss some classic attack techniques used by bootkits from their initial appearance to the present on two axes,including boot mode axis and attack phase axis.Next,we evaluate the race to the bottom of the system and the evolution process between bootkits and security mechanisms.At last,we present the possible future direction for bootkits in the context of continuous improvement of OS and firmware security mechanisms.

Analysis of genetic alterations identifies the frequent mutation of GNAS in colorectal laterally spreading tumors

Dear Editor,Colorectal cancer(CRC)is among the most commonly diagnosed cancer and the leading cause of cancer-related death worldwide[1].Most CRCs develop from adenomas.Laterally spreading tumors(LSTs)are non-polypoid superficial colorectal neoplasms(CRNs)that are larger than 1 cm and typically extend laterally along the luminal wall.Based on surface morphology,it can be classified into a granular or nongranular type.The pathological morphology of LST manifests only as adenoma or with cancer.Recent studies have characterized 45-79%of LSTs as high-grade intraepithelial neoplasia(HGIN)or submucosal invasion;and the risk of submucosal invasion increases with lesion size[2].Hence,LST is considered a precancerous CRC lesion.Patients with LSTs are usually asymptomatic and diagnosis typically occurs during physical examinations or screening colonoscopy.

Regular diet is non-inferior to restricted diet after polypectomy with decreased hospitalization length of stay and cost:a randomized–controlled trial

Background There are no data comparing a regular diet with a restricted diet after endoscopic polypectomy in patients with colorectal polyps.The current guidelines also did not provide the detailed information of dietary patterns after polypectomy.In this study,we aimed to evaluate the safety and efficacy of different diets on post-polypectomy outcomes.Methods A total of 302 patients with colorectal polyps who underwent polypectomy were prospectively enrolled between March 2019 and December 2019 in Nanfang Hospital(Guangzhou,China).Enrolled patients were then randomly assigned to a regular diet group or a restricted diet group after polypectomy.The study is a non-inferior design and the primary end point was the post-operative adverse events(AE)rate.Secondary end points included length of stay(LOS)and hospitalization cost.Results Among all the included patients,148 patients received a restricted diet and 154 patients received a regular diet after polypectomy.A total of 376 polyps were removed,with 183 polyps in the restricted diet group and 193 polyps in the regular diet group.Shorter LOS(4.0±1.4 vs 4.8±1.7,P<0.001)and lower hospitalization costs(7,701.63±2,579.07 vs 8,656.05±3,138.53,P=0.001)were observed in the regular diet group.In particular,there was no significant difference in 3-day AE rates between the restricted diet and the regular diet group(1.35%[2/148]vs 2.60%[4/154],P=0.685).Subgroup analysis looking at the number of polyps removed in each patient and different treatmentmodalities also showed similar findings.Conclusion Regular diet should be recommended after polypectomy for polyps<20mm as it can shorten LOS and save hospitalization costs.