Malicious PDF — malware analysis report

Static analysis result for SHA-256 535574f18121a34d…

MALICIOUS

PDF

68.8 KB Created: 2021-10-04 05:58:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: af2af3891c6e27281899e8d00c9eb319 SHA-1: 1fa704f67978ab11abc879eef6c877407de1b516 SHA-256: 535574f18121a34de5c45816542611b6de7e88c7355f3495aca7eed7910f1db5
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting an attempt to obscure the final malicious destination. The embedded URLs are likely used to redirect users to phishing sites or download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://cancelaria.pl/galeria/file/63322125892.pdf In PDF document text
    • https://mosconi.net/userfiles/file/jolobufuzofob.pdfIn PDF document text
    • https://fiscconsulting.com/userfiles/file/zedurusa.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/31196033761.pdfIn PDF document text
    • http://pepinieres-soupe.com/userfiles/file/7927234336.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d475f91afb---95531730300.pdfIn PDF document text
    • http://proleague.dk/userfiles/file/89594998284.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/vamaxepib.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/5fd5eafd03ff7c99d5887600ca9e573d/xevidakivitisajuxokagod.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/t65l3ul3uprhm9hh0c34hse517/sufokenewipugikafibezol.pdfIn PDF document text
    • http://notar-frings.de/userfiles/file/webosowefek.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/1d332ab81d667f00c994c6265319efd7/58980365984.pdfIn PDF document text
    • http://www.fan-consultants.com.tw/ezadmin/ckfinder/userfiles/files/1800838588.pdfIn PDF document text
    • http://mirsistem.com/depo/sayfaresim/file/11388791936.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142d0180a57a---sedixutalizufodudigef.pdfIn PDF document text
    • http://tekizolasyon.com/ckfinder/userfiles/files/roxanivikamiruduvesomad.pdfIn PDF document text
    • http://uralcomservis.ru/crn_fls/crn_files/76258931542.pdfIn PDF document text
    • http://brava-ekb.ru/userfiles/file/lodakumodowideku.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/icb2dmc9hs59ollvc2en47ihjp/bikiden.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad27529ac7---sasulal.pdfIn PDF document text
    • http://sunriverps.com/data/editor/file/sanogopezijasitul.pdfIn PDF document text
    • http://klaaswester.nl/img/file/sivotovobegepuwefekulibum.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/lopujefumotanef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=uk+pool+resultsPDF 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_off0000b24a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB24A 10088 bytes
SHA-256: d86cd7c4090da492c573a2d5e971d5bee3fb8f541709594f16fe43d8e3d8b9e8
font_01_sfnt_off0000c8f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8F7 14700 bytes
SHA-256: 6256f5173acfba05b46ceb75a10586bcd578f2b6c9d26a95b000021fe00253e2
font_02_sfnt_off0000edaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDAA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1