Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4de1b9e407a3f6a…

MALICIOUS

PDF

71.0 KB Created: 2021-08-04 07:51:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ff053fc2326145298974e2cead62e198 SHA-1: 848c864d86d172b77f9366844e21a1f759877d88 SHA-256: b4de1b9e407a3f6a781bc693d9b63024b7f54ee1e4cf53d3383ced11738969f9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous embedded URLs that point to compromised WordPress sites and other disposable hosting. These links likely serve as lures for phishing attacks or to distribute further malware. No scripts were extracted, but the PDF structure itself facilitates redirection to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://laborke.ru/uplcv?utm_term=teaching+homographs+5th+grade PDF link annotation
    • http://gdbchurch.com/clients/43262/File/sogete.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160901adb0a6d1---gufupe.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/4r7h8cpg9l2e1e99fpii446nbr/velozovesimawupemez.pdfIn PDF document text
    • http://trendybiz.in/usersfiles/file/dividimupekijim.pdfIn PDF document text
    • https://urbanplace.me/wp-content/plugins/super-forms/uploads/php/files/33dbc1173cbf5f4305e940e557708ff3/dizorijemakenawe.pdfIn PDF document text
    • https://havanic.com/cache/fck_files/file/ropuxujutujoruxunakeze.pdfIn PDF document text
    • http://crystal-lamp.ru/uploads/files/sukefupozaxa.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/646d1bb893c8d273015ce2424fb102aa/roxowineviwon.pdfIn PDF document text
    • https://tedvandergulik.nl/userimages/file/gibarukidizowuze.pdfIn PDF document text
    • http://getampedmag.com/ckfinder/userfiles/files/6284056563.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9ee999e02d.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/7be17644e29e032923cc1b705728454b/57157666030.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a99af9aca8c---27085019893.pdfIn PDF document text
    • http://xn--h1aaebajlcgx.xn--p1ai/sadm_files/piwexepuvuvu.pdfIn PDF document text
    • http://kiiga.ru/userfiles/file/60089652637.pdfIn PDF document text
    • http://mousike.it/img_ins/files/zegufafaridizoweg.pdfIn PDF document text
    • http://itssilvertime.com/clients/2/24/24efe347a73a8ce028152bf895bc11a7/File/xebowiredajifuf.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/3721eaa4762723dc22fd5e97487a9627/84895143217.pdfIn PDF document text
    • 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_off0000b92d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB92D 14268 bytes
SHA-256: 244b96c637112c10b4c5a93b5500cb555c645a2ebee641ca9ae3a95407d91589
font_01_sfnt_off0000dceb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCEB 11012 bytes
SHA-256: a2db31dee79858765121d17629407ee59640d0fdde66261dd0aee13f80c3ee9b
font_02_sfnt_off0000f62f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF62F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1