Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3b8dfd76d9fc000…

MALICIOUS

PDF

73.4 KB Created: 2021-09-21 13:43:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1592288f85d476724177899900df577b SHA-1: 5081b31108c574ac7f73c3e76730d820c20b1ad7 SHA-256: a3b8dfd76d9fc000dd7e1db902ea1a84e5db002e73137a938354c3cbd29a6345
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to suspicious PDF files on disposable hosting, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded links are consistent with techniques used to redirect users to malicious sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://execdentalclinic.com/uploads/ckfinder/userfiles/files/kaxosonijisufonobivefa.pdf In PDF document text
    • http://solarexperte.ch/fckeditor/editor/images/file/8120000602.pdfIn PDF document text
    • http://cukrarska-vyroba.cz/UserFiles/File/putobitibamaxepo.pdfIn PDF document text
    • http://pibar.tw/uploads/files/202109121300157016.pdfIn PDF document text
    • http://torgoborud.org/images/file/kagidinojuvuweriluburo.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7a2304b43---50922780228.pdfIn PDF document text
    • http://fairfresh.net/assets/admin/ckeditorimage/files/56740733978.pdfIn PDF document text
    • https://konteshamamotu.com/userfiles/file/60730273145.pdfIn PDF document text
    • http://sitoad.com/bbqjoekey/files/202109032007409200.pdfIn PDF document text
    • https://monographie.com/ckfinder/userfiles/files/28469989483.pdfIn PDF document text
    • http://kccmaul.com/files/files/widovililotejitiwareropad.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16140710ee9b54---68120966482.pdfIn PDF document text
    • http://zespolbahamas.pl/zdjecia/file/fewaxuvivoge.pdfIn PDF document text
    • http://bugaboo-buffalo.eu/UserFiles/File/76799832298.pdfIn PDF document text
    • http://reklamaopole.pl/userfiles/file/xesibemanopiwaxurotovotov.pdfIn PDF document text
    • http://valkexclusief.reviews/app/webroot/files/userfiles/files/74846019000.pdfIn PDF document text
    • https://botroul.be/uploads/30009667902.pdfIn PDF document text
    • https://arichaindia.com/userfiles/file/talogezafezatixap.pdfIn PDF document text
    • http://csc-027.com/userfiles/file/20210921171457_277t9x.pdfIn PDF document text
    • https://responsible-tourism-alliance.com/content_file/files/didiporodosemaredopuz.pdfIn PDF document text
    • http://nanoservice.cz/upload/file/41551452657.pdfIn PDF document text
    • http://pensionpoint.cz/userfiles/files/jejalori.pdfIn PDF document text
    • http://chengzechem.com/upload/files/juvawelafeseguluvetitow.pdfIn PDF document text
    • http://short-story.ru/upload/file/zivedagekukolajawulufiwug.pdfIn PDF document text
    • https://mirrorlink.com/public/files/files/79670933152.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=download+torrent+fast+and+furious+9PDF 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_off0000b9bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9BC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d1d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1D3 10700 bytes
SHA-256: 5fd8f6165a3ff36fc1e0fbac68ed440cf6d3f7f0a75d1e64f0e94f9f811c1df6
font_02_sfnt_off0000ea93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA93 17504 bytes
SHA-256: 41d6ed025619e75cd2fab63e5640e0eb6bd7c1a04f4ba0bc6920d4f2496007dc