Malicious PDF — malware analysis report

Static analysis result for SHA-256 750de8ffd704d6e1…

MALICIOUS

PDF

85.5 KB Created: 2021-07-07 15:12:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 5896a5811625bda1bbd035304439c0b6 SHA-1: dd3285db11ef8cca1c0f8ed257a7130efd96e21d SHA-256: 750de8ffd704d6e16919c600536450a9a921e5634b2d5bbde5df673275135515
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a phishing or trojan threat. It functions as a link farm, with numerous embedded URLs pointing to external sites, some of which are hosted on compromised WordPress installations. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a vehicle for the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://volkshilfe-ktn.at/images/content/files/vupinusatufokojurukugemup.pdf In PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/tizofediximusov.pdfIn PDF document text
    • http://sevimticaret.net/userfiles/file/21099420408.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b4ca69b9bd2---wonutuvow.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071d52141ff1---38752913604.pdfIn PDF document text
    • https://carpanea.it/wp-content/plugins/super-forms/uploads/php/files/f5197f753891e493c4590a5bcc38ffab/87277753547.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160c8e8f0a1297---jipunilekadiditaker.pdfIn PDF document text
    • https://108pizza.pl/uploads/userfiles/files/18037328274.pdfIn PDF document text
    • https://nbtele.com/en/cache/fck_files/file/42595815403.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160db66daa9e20---76843989243.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/a294e0121e3579a6dd1ae39d4a032bbd/raxipu.pdfIn PDF document text
    • http://vamaconsulting.sk/userfiles/file/renirugusovixerasa.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/160816a7809719---92011328772.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/6a19beb7c65ffc670e7e24e73d6c50ee/jugarot.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/baxekafedifutakado.pdfIn PDF document text
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/goqrmfrqbcccga0s6h65di5hoi/68697305366.pdfIn PDF document text
    • http://laser-piskovani.cz/democms/userfiles/file/zidepiro.pdfIn PDF document text
    • http://mjsolankifoundation.com/fck/imagesfile/nigejejukuli.pdfIn PDF document text
    • http://scoutpate.com/userfiles/file/85071251446.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/3fjuldidij6fuubd1tkl6c9rgf/36542518335.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/fch4huhlkhopsoadmrq5m3b8go/68895448249.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f8ff44f7d2---bomudenunogokofakad.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/97d18aa4026f22bf281e4e54f4616898/96593818572.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=singing+in+roundsPDF link annotation
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/61e87d51280e4a8b111e43a3dbf7dc40/26259720891.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_off0000ed70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED70 10160 bytes
SHA-256: b0c7f27eefcde4287181792db3bba71e9b99f49f18d817256436462d19bb0b12
font_01_sfnt_off000103f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103F0 17544 bytes
SHA-256: f21ee6b8ce96f62aab137133855f662bd7967ecff2ad6ceb7a2229fcf0fa0806
font_02_sfnt_off000131c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1