Prelims Sure Shot 

1. BlackRock Android Malware

Why in News

Recently, a security firm has alerted about a new malware called BlackRock which targets social, communication, and dating apps.

 

Key Points

• Blackrock is a banking Trojan and said to be an enhanced version of existing Xerxes malware which itself is a variant of the LokiBot Android trojan.
• A trojan is any type of malicious program disguised as a legitimate one. Often, they are designed to steal sensitive information (login credentials, account numbers, financial information, credit card information, and the like) from users.
• Banking trojans once installed onto a client machine use a variety of techniques to create botnets, steal credentials, inject malicious code into browsers, or steal money.

 

• Functioning: It collects user information by abusing the Accessibility Service of Android and overlaying a fake screen on top of a genuine app. It uses Android DPC (Device Policy Controller) to provide access to other permissions.

 

• Concerns: It surfaces as a google update. The malware is said to have the design to overlay attacks, send, spam, and steal SMS messages as well as lock the victim in the launcher activity. It can also act as a keylogger (i.e. track the keys struck on a keyboard), which essentially could help a hacker to acquire financial information.

 

• Despite being a banking Trojan, BlackRock is said to target non-financial apps. It targets a total of 337 apps, which is significantly higher than any of the already known malicious code. It makes antivirus applications useless.

 

2. Bathynomus raksasa: Isopod Species

Why in News

Recently, scientists have reported the discovery of the first super giant isopod species in the eastern Indian Ocean named ‘Bathynomus raksasa’. It has been described as the ‘cockroach of the sea’. A team of researchers from Singapore discovered it while exploring waters of the Indian Ocean in Bantan, off the southern coast of West Java in Indonesia in 2018.

 

Key Points

Super Giant Isopod:

• The Bathynomus raksasa is a super giant isopod in the genus
• Isopods are marine invertebrates (animals without backbones) that belong to the greater crustacean group of animals, which also includes crabs and shrimp. They live in many different types of habitat, from mountains and deserts to the deep sea.
• Isopods that reach 50 cm are referred to as supergiants. The largest isopod species are from the genus Bathynomus.

Features:

• It has 14 legs but uses these only to crawl along the bed of oceans in search of food. It measures around 50 cm in length, which is big for isopods, which normally do not grow beyond 33 cm.
• The only member of the isopod species that exceeds the raksasa in size is the Bathynomus giganteus, which is commonly found in the deep waters of the western Atlantic Ocean.
• It is the first recorded species of the genus Bathynomus from Indonesia. It is the sixth ‘supergiant’ species from the Indo-West Pacific.

 

3. RADT Vs RT-PCR

 

Why in News

Recently, New Delhi’s Covid-19 testing strategy has become controversial due to the low level of RT-PCR (Reverse Transcription Polymerase Chain Reaction) re-testing in persons tested negative in RADT (Rapid Antigen Detection Tests). Using RADT widely without following up with adequate retests contradicts Indian Council of Medical Research (ICMR) guidelines on use of the RADT test.

 

Key Points

ICMR Guidelines:

• RADT ought to be used only in containment zones, hotspots, hospital settings and laboratories among those who manifested one or other symptoms of the disease, influenza-like illnesses. People with co-morbidities who were asymptomatic and high-risk contacts of those confirmed positive.
• Those who tested ‘negative’ and who were suspected by the clinicians to be harboring the disease ought to be tested sequentially by RT-PCR to rule out infection and higher chances of false negatives.
• Those who test positive don’t need a re-test and must be considered positive.

 

Testing in New Delhi:

• From 18 June – 16 July, it has conducted 3, 05,820 RADT. Of these, 2,85,225 tests came ‘negative’ and out of them only, 1,670 were chosen for re-test by RTPCR and 262 of these were confirmed positive.
• Only 1 in 200 of those who tested negative in an antigen test to detect possible coronavirus cases were re-tested, which is against the given guidelines of ICMR.
• Of those re-tested with RT-PCR, around 15% tested positive, which is higher than the RADT positive results i.e. 6%.

 

Arguments for Low Re-tests:

• Re-testing everyone would defeat the purpose of having another (rapid antigen) test. The RT-PCR test takes a minimum of 2-5 hours including the time taken for sample transportation.
• This limits the widespread use of the test and also impedes quick augmentation of testing capacity in various containment zones and hospital settings.
• In RADT, the maximum duration for interpreting a positive or negative test is 30 minutes, thus a quicker complement to the standard RT-PCR

 

Arguments Against:

• The consequence of indiscriminately deploying antigen tests would mean expanding the number of tests and presenting a lower positivity rate while not necessarily being able to reliably establish the extent of the spread of the coronavirus in the population.
• A low level of re-testing with RT-PCR in persons who are testing antigen negative will underestimate the cases and make the tracking inaccurate.
• RADT It is a test on swabbed nasal samples that detects antigens (foreign substances that induce an immune response in the body) that are found on or within the SARS-CoV-2
• It is a point-of-care test, performed outside the conventional laboratory setting, and is used to quickly obtain a diagnostic result.
• Like RT-PCR, the rapid antigen detection test too seeks to detect the virus rather than the antibodies produced by the body.
• While the mechanism is different, the most significant difference between the two is time. As the ICMR has pointed out, the RT-PCR test takes a minimum of 2-5 hours including the time taken for sample transportation.
• In a reliable rapid antigen detection test, the maximum duration for interpreting a positive or negative test is 30 minutes.

 

RT-PCR Test

• Kary Mullis, the American biochemist invented the PCR technique. He was awarded the Nobel Prize for Chemistry in 1993. Under this, copies of a segment of DNA (deoxyribonucleic acid) are created using an enzyme called Polymerase.
• The ‘chain reaction’ signifies how the DNA fragments are copied, exponentially — one is copied into two, the two are copied into four, and so on.
• A fluorescent DNA binding dye called the “probe” is added to DNA, which shows the presence of the virus on a
• However, coronavirus is made of RNA (ribonucleic acid). Therefore to detect coronavirus, RNA is converted into DNA using a technique called reverse transcription. A ‘reverse transcriptase’ enzyme converts the RNA into DNA. Copies of the DNA are then made and amplified.