Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d81794da290e113…

MALICIOUS

PDF

73.5 KB Created: 2021-08-31 23:08:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 50a2c24b5678776511984527b6ce352f SHA-1: f90dc8f089344ae5c9a8714c8f091da4728a3911 SHA-256: 4d81794da290e113174837947f5a12944831fefad3ee119051a09f4262f087f9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document functions as a link farm, with numerous URLs pointing to compromised WordPress sites and other domains. These links likely serve to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/0vai6psm3hmvhs6kc0hltr8a21/10254860302.pdf In PDF document text
    • https://immobilgold.com/file/sugalav.pdfIn PDF document text
    • https://digireg.es/upload/45902993256.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/21048710107.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/16082a9c9c4ec7---boxorube.pdfIn PDF document text
    • http://cephedanismani.com/images/pages/file/vopesesekib.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160830a85bbe92---puxepuneliw.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/3d707ed7d5c530a41ac9fe8cd53f70b3/11790343469.pdfIn PDF document text
    • http://biosite.ru/images/news/file/86184695403.pdfIn PDF document text
    • http://arcstema.com/userfiles/files/dipefijanukiwufujawadi.pdfIn PDF document text
    • https://elpollopaulino.com/cenavarra_userfiles/files/25395238633.pdfIn PDF document text
    • https://rockeit.com/userfiles/file/79033168464.pdfIn PDF document text
    • https://palet-school.com/files/files/mababijowonaroner.pdfIn PDF document text
    • http://chapelguild.com/images/usr/23935167491.pdfIn PDF document text
    • http://dmscsmartlifeblog.com/userfiles/files/golujofivopeduduj.pdfIn PDF document text
    • http://izeninfo.net/admin/upload/files/2110821890.pdfIn PDF document text
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/5e335c6721fe5424afc0a74c266879e2/37465231897.pdfIn PDF document text
    • https://digicpictures.com/downloads/walikixanopixuwalewew.pdfIn PDF document text
    • https://olgapopovaphoto.com/wp-content/plugins/super-forms/uploads/php/files/f563f8f2a40358ba975b9cbeca4e236b/nalumowodufujivolix.pdfIn PDF document text
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/i0k01icsfcbbi3ud6junu1bjs1/26816660591.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/51156911141.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///sifosexobividadat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=oucher+pain+rating+scalePDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee345fddba8---89291286344.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_off0000bf0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF0C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d723.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD723 10660 bytes
SHA-256: 4e8c5eb68af12dcf63be0bc3f538f0cb9e0154add62458ae4c67684cf8fd30fb
font_02_sfnt_off0000ef8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF8F 15968 bytes
SHA-256: 5384b3cbad271868a2a78dc672b6b24c382db1277c753bdc52271ba0fe321c8c