Malicious PDF — malware analysis report

Static analysis result for SHA-256 42c5c16417fc8063…

MALICIOUS

PDF

83.0 KB Created: 2021-09-16 16:28:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: def65b2a3106d136798730d3a05ccf2d SHA-1: 736c284d9d3818cf8510bf90f4a126322ea55100 SHA-256: 42c5c16417fc806340a6a32c24fd958e8402fec15b0eabb6a1fe3ea7013ca666
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The document body is heavily obfuscated, preventing analysis of its direct content, but the presence of numerous links suggests an intent to redirect users to potentially harmful destinations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://venus-forever.com/image/files/33558039309.pdf In PDF document text
    • http://novelinternationalschool.com/ckfinder/userfiles/files/rozanijapekomurolejod.pdfIn PDF document text
    • http://mtkshop.com/images/uploads/file/22347921765.pdfIn PDF document text
    • http://tw-tms.com/uploadpic/xw/files/60990516291.pdfIn PDF document text
    • https://barrier.exma.cl/ckfinder/userfiles/files/52171265838.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/b15lihbc3t5flbm7nfhvgqt8g5/tojanutenu.pdfIn PDF document text
    • http://vitalchurchesinstitute.com/files/file/83524196997.pdfIn PDF document text
    • http://sunmoon-glory.com/web/upload/files/gobap.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161408fbc5cb8f---9701016122.pdfIn PDF document text
    • https://hotelgaric.com/upload/datoteke/zagutaxewevipofowo.pdfIn PDF document text
    • http://h-p-n.fr/catalogue_dynamique/file/21660547800.pdfIn PDF document text
    • https://www.totspotdaynursery.co.uk/ckfinder/userfiles/files/piziwozafifedatav.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/ha1pbltilbacpq97me59mboblf/serulokelepixu.pdfIn PDF document text
    • http://khaskhaan.mn/uploads/userfiles/files/rinofoxofotefapox.pdfIn PDF document text
    • https://mandarinkinesiska.com/userfiles/file/19307540474.pdfIn PDF document text
    • https://bankubezpieczen.pl/userfiles/file/22952280305.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/16139f87396741---zesedemepero.pdfIn PDF document text
    • http://studiomanzella.com/userfiles/files/65411491665.pdfIn PDF document text
    • https://martensmgt.com/business_school/uploads/file/zibonot.pdfIn PDF document text
    • http://www.culturehousesun.org/photos/file/kufizovej.pdfIn PDF document text
    • http://qamsar.org/userfiles/files/58297458866.pdfIn PDF document text
    • https://spandoekland.nl/userfiles/file/lokugadidinunaba.pdfIn PDF document text
    • https://fundacjaartfreeart.pl/userfiles/file/nujobarusinuzelomaj.pdfIn PDF document text
    • http://bioaec.com/userfiles/files/pofubepazobijowov.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/6ceaf5014e07e0d2a73961246e1eedec/devibobatoto.pdfIn PDF document text
    • https://gopherscopes.com/userfiles/file/mijugitodisim.pdfIn PDF document text
    • http://hurtglass.pl/upload/file/bajeworewewavonexexopu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=os+used+in+mobilesPDF 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_off0000e167.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE167 10312 bytes
SHA-256: 265fa688e3fb51ce888f9ea06b32d43193b5fba0fc62de81ccc7770e298121f3
font_01_sfnt_off0000f88b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF88B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001109d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1109D 17708 bytes
SHA-256: 85eea0af5114bbbd3fcb4c38380e7097c8983b4a706dbfb0fcda1285c73d28dd