Malicious PDF — malware analysis report

Static analysis result for SHA-256 537a55d7e11db2eb…

MALICIOUS

PDF

88.2 KB Created: 2021-06-30 16:43:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 820654f40014001f48c48198e460fd19 SHA-1: e1f4321ddaa31d21fbabd7fa7a9320be2e9e3b75 SHA-256: 537a55d7e11db2eb748115942517bb672737876e472e161564157419370c9060
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1609424fd89a59---batixewin.pdf In PDF document text
    • http://ash-graphy.com/userfiles/file/biniduvuxeli.pdfIn PDF document text
    • http://chromowane.com/userfiles/file/sajaz.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087a4cbf3817---80376934296.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/306e507606470bbdf23cef0db23e827e/36836197292.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1608488f2a4f21---zafabolusetozotetalasageb.pdfIn PDF document text
    • https://a5productions.com/home/a5pro/public_html/ckfinder/userfiles/files/nekog.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c7252b8225---6414795707.pdfIn PDF document text
    • http://www.conectadoscomdeus.tv/arquivos/file/44457122464.pdfIn PDF document text
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/54ccm7b036uu0npn98d6lebp85/popir.pdfIn PDF document text
    • http://m2m2design.com/userfiles/mozalexelaxinakugujaxexot.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b38acb5c9fa---93946428971.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd0f4ac37e---57859544317.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6958cac5a4---63309916958.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/1a48fbdca61d2f4f40029e9fa4c5dc21/68649362271.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d58a5317db---93065349232.pdfIn PDF document text
    • https://businesslife.com/content/file/61004069788.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160946f7edb5eb---97195316716.pdfIn PDF document text
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/1608666ab6cc1b---wijuximitalukazidaludatem.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/9uknof0uaqiql7aehh61mf1521/58236923632.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607173e2e7428---31446316931.pdfIn PDF document text
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/fb4e82f1dd3de68fb64cac4958c18d03/keniwuvadufolibulazur.pdfIn PDF document text
    • http://granite1962.com/clients/869125/File/xamexupagijuwajokofosixo.pdfIn PDF document text
    • https://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/qppunfq6c3r5aotop65fbkhvjj/5783696531.pdfIn PDF document text
    • http://ntrc.biz/clients/f/f0/f0759d16aca5b3dfc9163ee994587b7f/File/28462921437.pdfIn PDF document text
    • https://angelsstaff.com/uploads/file/27754644941.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=is+eating+5+apples+a+day+bad+for+youPDF link annotation
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/98aabb30bf0bde409ee15fa570b67919/20021233904.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_off0000f28e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF28E 11112 bytes
SHA-256: f7025c44bc2136a2d109ca343795693b29bda9d530cc4f5c20754547a5b148ad
font_01_sfnt_off00010c38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C38 17300 bytes
SHA-256: 844e1117090cbad28284ec213b2c2edcc6642b97c90b998c534605b1ef523a13
font_02_sfnt_off00013951.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13951 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1