Abuse Report

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To: report@abuseradar.com
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Subject: Abuse Report: Active portscan/attack detected from 146.103.24.158
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Message-Id: <20260516173214.3BC16C14A29@cheems.de.box.skhron.com.ua>
Date: Sat, 16 May 2026 17:32:12 +0000 (UTC)
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This is an automated abuse complaint regarding suspection of device infecti=
on
within your network behind IP address 146.103.24.158
---

Our isolated systems has received multiple unsolicited incoming connections
from an IP address under your control (abuse-mailbox as per RIR database). =
All
unsolicited connections reported below have completed three-way handshake
procedure defined per Transmission Control Protocol (TCP). This ensures tha=
t
our evidence was not tampered upon any external party posessing a source IP
address spoofing capability, because three-way handshake procedure requires
both receiving (device within our network) and sending (device within your
network) parties to receive reply of another party to complete handshake.

The aforementioned isolated systems within our network are hosted at unused=
 IP
address space and are implemented as a TCP listener, so that we can be sure=
 our
evidence actually covering "unsolicited" and "not spoofed" activity.

The activity we are reporting is often referred to as "service probing" or
"banner grabbing". Unlike typical "port scan" type of abuse complaints you
might receive, our complaints are not induced by a single or multiple TCP
packets with SYN flag set. Instead, as was mentioned previously, three-way
handshake procedure is required. To eliminate possible false-positive alert=
s
caused by human typo, abuse complaint is generated only upon having four (4=
)
distinct successful connections as per (Source IP; Destination IP; Destinat=
ion
Port) tuple.

To minimize "Internet background noise" our network observes, the reported =
IP
address was temporarily banned. Do not worry, it will be unblocked
automatically soon. If it is the first report for this IP address within 90
days, block lasts 24 hours. Each following report within this timeframe ext=
ends
blocking duration for 24 hours.

As for implications for your network, we suspect that device within your
network is infected with a malware. However, sometimes there are another
reasons, namely:

- device hosts publicly accessible proxy or VPN (either intentionally, due =
to
  software misconfiguration or due to usage of "proxyware" type of software=
);
- device is infected with a malware (for example, networking worm, most fre=
quently
  this happens with IoT and DVR/IP cameras);
- device (for example, server) is used by an malicious actor for exploitati=
on
  purposes (see "unethical hacking");
- device is used by a legitimate Internet security researchers team that ca=
n be
  clearly attributed using Forward-confirmed reverse DNS (FCrDNS).

Given exact reason in this situation, you would like either to communicate =
with
your client to address this issue as per Terms of Service of your organizat=
ion
or notify us of legitimate nature of this activity. When it comes to legiti=
mate
security researchers, we are always co-operating to whitelist your networks=
 as
long as FCrDNS is valid.

Please note that we are providing hosting services, hence you are strongly
discouraged from blocking any of the destination IP addresses mentioned bel=
ow.

If these complaints are considered irrelevant by your team for any reason, =
do
not hesitate to let us know by replying to this letter. We will exclude you=
r
abuse-mailbox from receiving these abuse complaints in the future.

Incident details are attached below. Please note that due to some automated
abuse complaint processing systems parsing destination IP addresses as ones
involved to this report, we are redacting destination IP addresses replacin=
g
all "." and ":" characters with "x".

```
Timestamp                SrcIP          SrcPort DstIP          DstPort
2026-05-16T17:11:19.747Z 146.103.24.158 9866    88x218x206x150 445   =20
2026-05-16T17:11:27.088Z 146.103.24.158 10148   88x218x206x2   445   =20
2026-05-16T17:21:40.308Z 146.103.24.158 14846   88x218x206x4   445   =20
2026-05-16T17:32:04.728Z 146.103.24.158 13655   88x218x206x5   445   =20
----------------------------------------------------------------------
```

As was mentioned previously, the table above lists all unsolicited TCP
connections that have completed three-way handshake. This prevents us from
producing false-positive alerts. It is worth to note that we aren't closing=
 the
connection immediately after three-way handshake was completed, thus you sh=
ould
see communication from your sFlow monitoring. If you are using NetFlow or
IPFIX, you should be able to see all four (4) flows. If you don't implement=
 any
of those, do not hesitate to ask us for more detailed logs.

Kind regards,
Network department
Skhron