Malicious PDF — malware analysis report

Static analysis result for SHA-256 c771d0757ecac369…

MALICIOUS

PDF

81.6 KB Created: 2021-09-01 15:49:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 18c08cf3f6a0a366fc66ffa35e8201c5 SHA-1: d616389bfe1989497f8a47b7ea97cc8b6771cb09 SHA-256: c771d0757ecac369cacfa86350ae503ab1dd6b89ef612519985334853b385677
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics identified it as a link farm on compromised CMS uploads, pointing to multiple distinct hosts. The presence of external URIs and the structure suggest an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1623343bb5---26400480869.pdf In PDF document text
    • https://eobliecky.sk/userfiles/file/84291719467.pdfIn PDF document text
    • http://bugaboo-buffalo.eu/UserFiles/File/nogiguvaweliwofifuwo.pdfIn PDF document text
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/vakdipns36ai5ubg8h3het5snd/24394255628.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1607e12c317a67---86616936148.pdfIn PDF document text
    • http://alexhoffordphotography.com/temp/files/file/bonuzudisojanerevul.pdfIn PDF document text
    • http://geraldinekilkelly.ie/52143190955.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/1gd3r5drep5gont2qveupeqca2/faxalumuborigife.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160bb06c37721e---kefedifelutesowux.pdfIn PDF document text
    • http://alpinedelhi.com/userfiles/files/duvavejuvulowigo.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/160b8507d3d142---92405267262.pdfIn PDF document text
    • http://cokhibaosang.com/media/ftp/file/virakupelus.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607843cb2d39e---givabonewagakadow.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/zigopulajididepi.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/94ced207ec9b5e2c9651bda1eb65db12/55160441375.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc6548853c---88537521139.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16085d89d316e8---18709065162.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160cd31a5ca2d7---pitenovatupalisosas.pdfIn PDF document text
    • http://ankamet.com/userfiles/file/wesotajinofazunoze.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097e25d6dcad---banejaxidisefolagufekit.pdfIn PDF document text
    • https://ketdoanbus.com/webroot/img/files/dopizumakotokikoj.pdfIn PDF document text
    • http://masan315.net/board/imagefile/file/60388147912.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/elbrutscqrmauoea09rdt9rno6/pufoxaruvawepitivulemomef.pdfIn PDF document text
    • http://siciny.eu/userfiles/file/3799743394.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/16078706b04b56---42328707361.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160fb831a415e3---bigixasuz.pdfIn PDF document text
    • http://didaconcept.com/admin/fckeditor/file/97843560311.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=ecosystem+services+worksheet+answer+keyPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB67 16800 bytes
SHA-256: f7a4a8247afa73e76b5016e26bf31c734c7af4f5c813a4d6f0a0788e8511d701
font_01_sfnt_off000106ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106BA 10792 bytes
SHA-256: 59aed7aec7bc199b3c56234b95e4f39fb4782f7e42c68e22015d4343ec83dd14
font_02_sfnt_off00011f7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F7F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1