Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a8f857633016e0c…

MALICIOUS

PDF

91.5 KB Created: 2021-09-05 00:53:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 43c857922640addf686c66e30ab53aa0 SHA-1: 12a02d70367a69dec7ed290308075001cb35a6e2 SHA-256: 5a8f857633016e0c8942c6a16904e4f867732661526147c8ee30496bbe7cf677
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to lead users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 http://goodslib.com/userfiles/files/kawotariwid.pdf In PDF document text
    • http://kingtonkatsu.com/uploads/files/90026411617.pdfIn PDF document text
    • http://kovovyroba-nosniky.cz/UserFiles/File/15300187835.pdfIn PDF document text
    • http://hevolta.com/upload/file/87012067962.pdfIn PDF document text
    • http://tc-antey.ru/uploads/files/71809405504.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160bfba0bbf719---30283153590.pdfIn PDF document text
    • https://baileyelectrical.services/wp-content/plugins/super-forms/uploads/php/files/j7oelittfbn5jv2qtf4jokbcue/44060771773.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/13502bf888919bb3b42611b07554da25/48018506039.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608051c70eb8a---99176118971.pdfIn PDF document text
    • https://masihpt1.com/contents/files/97969850910.pdfIn PDF document text
    • http://liily.jp/upload/file/20210722135222.pdfIn PDF document text
    • http://turatabor.hu/media/xitenemuku.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/14u3m18pq7550hf2ta3s8pjlgj/16244118001.pdfIn PDF document text
    • http://prosquash.by/data/11399795097.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16072ada7be3aa---zuragekopejakovav.pdfIn PDF document text
    • http://dangkydoanhnghiep.org/hinhanh_fckeditor/file/37625030968.pdfIn PDF document text
    • http://umrllc.com/userfiles/files/vijaxikenesiwo.pdfIn PDF document text
    • http://locthanhwindow.com/img_duhoc/files/46007337266.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c1026c721ac---36380896130.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b8fe987cf5a---13262556778.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/dde834284dd76033c5fed7bc2879bd09/50359311197.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/7480548547.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/161299b6abaef4---fisizezatarutasixojit.pdfIn PDF document text
    • http://alliance-ltd.com/userfiles/befinumamibafiresezavala.pdfIn PDF document text
    • https://autotrans911.com/thread/admin/uploads/file/38974430594.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ffe0179df5c---84342190248.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=european+resuscitation+council+guidelines+2018+pdfPDF 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_off0000f913.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF913 11380 bytes
SHA-256: b8e48ca793fba21a6259e582973dd08876d1f254b92d4bdca2949864c7a0287a
font_01_sfnt_off000113dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113DD 20088 bytes
SHA-256: 5dcb8f7ed5a9b94da2ddc12a68e93d574f14ed8af097fcf5b04ceb692eb28bf5
font_02_sfnt_off000147eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1