Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8de17d0758a459e…

MALICIOUS

PDF

80.5 KB Created: 2021-09-10 18:01:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d89b44c11a52d530c17b0f058e1a2451 SHA-1: ce5125610803fd282e29d9b28440e2a5f21106b0 SHA-256: b8de17d0758a459e86fec7f6199bd5b586490c238ab697fcd3c52058c181156b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://huntic.ru/uplcv?utm_term=calculus+early+transcendentals+third+edition+pdf PDF link annotation
    • http://tsg-vaganovskoe.ru/ckfinder/userfiles/files/38805180415.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1613649872524e---gudopafelo.pdfIn PDF document text
    • http://hyundai-baoloc.com/luutru/files/vosulitoj.pdfIn PDF document text
    • http://xindeshiye.com/uploadfile/file///2021090209444152.pdfIn PDF document text
    • http://sarkanyhajo.hu/files/file/91826890051.pdfIn PDF document text
    • http://fszhenjia.com/upfolder/e/files/20210903081108.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613611c813c55---50241429924.pdfIn PDF document text
    • https://watertorens.nl/userfiles/file/mafebosomonukevegeza.pdfIn PDF document text
    • https://tenshinorchids.com/FCKeditor_upload/file/98385836651.pdfIn PDF document text
    • http://sinners-party.de/media/file/ronakisarobuv.pdfIn PDF document text
    • https://hediyelikhanem.com/calisma2/files/uploads/ripavidevibijunu.pdfIn PDF document text
    • http://slovbau.sk/test/userfiles/file/xaraxajot.pdfIn PDF document text
    • http://hometextiles-consultant.com/ckfinder/userfiles/files/68329212773.pdfIn PDF document text
    • http://robertwestlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fusuzikujakuserori.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/busufib.pdfIn PDF document text
    • http://ardeche.proximeo.com/ckfinder/userfiles/files/namasiruvavo.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/161316480697db---zeminijob.pdfIn PDF document text
    • http://jeanthompson.nl/ckfinder/userfiles/files/98811039398.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/dokoxajogifefopanafosit.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/161337e9b40fcd---59038186721.pdfIn PDF document text
    • http://tercovci.cz/files/file/posovixivuwoji.pdfIn PDF document text
    • https://iwanbim.iwan.co/userfiles/files/kikigidudikatibejifono.pdfIn PDF document text
    • http://carszana.com/image/upload/File/99756596543.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/86323557421.pdfIn PDF document text
    • https://fullhousetourism.com/UploadFiles/file/20210909230752155.pdfIn PDF document text
    • http://surmounttravel.com/userfiles/files/vozagokariturumelofe.pdfIn PDF document text
    • http://ozt.zielonetarasy-cieplice.pl/uploads/userfiles/files/14782228431.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_off0000d32b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD32B 18164 bytes
SHA-256: 84d6f774a760af00df75a19582d1e896a356a814552b8be9863220291bb86c13
font_01_sfnt_off0001029e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1029E 10960 bytes
SHA-256: 65f7e7e811927a257d5b8e0c743c794600aab6dc5c1f493577e210d836f7d991
font_02_sfnt_off00011c07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C07 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1