Malicious PDF — malware analysis report

Static analysis result for SHA-256 91fa81eb74c3a3b9…

MALICIOUS

PDF

81.1 KB Created: 2021-09-01 01:25:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: e245487c2d5a52cd72e0c88434ff3ec6 SHA-1: c7125663ca9d2bf0976b01e5cf7fad6e1eaf9063 SHA-256: 91fa81eb74c3a3b997a7187e7a73f62d4d40e49e77f81bfba0c3483e4ee79223
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

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 0.9968

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://krisoc.ru/uplcv?utm_term=house+design+for+slope+area PDF link annotation
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160866b6a88804---30852418091.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-5-16/20210516203425852275.pdfIn PDF document text
    • https://concertwristband.com/resimler/files/20839438274.pdfIn PDF document text
    • https://tessuno.com/upload/files/60f71b5db19ac.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dcb98d36aa---70782563956.pdfIn PDF document text
    • http://sinhorelli.com/userfiles/file/rusagixafasujisuda.pdfIn PDF document text
    • https://playerpress.com/ckfinder/userfiles/files/bejoku.pdfIn PDF document text
    • https://kogan-photo.ru/wp-content/plugins/super-forms/uploads/php/files/43b746cbf99d5c71ebdb9a8fe2d06d2c/pigaliwudavodovofomirod.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/m79usuhkf1kj92aa7s6loapc71/kusaxuvotujodevedimerome.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612695d45a440---pukijisob.pdfIn PDF document text
    • http://tafgambiatours.com/userfiles/file/23569018139.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160845fd0d5c55---97303772781.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606caac022259---58892507075.pdfIn PDF document text
    • https://lenaoyunlar.com/calisma2/files/uploads/4187414561.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/mlurpdsemvbh2520i5a92gctf3/wetiwaxuximumoweja.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075b949c9504---zulezujinubam.pdfIn PDF document text
    • http://unnatiwelfareorganization.com/ckfinder/userfiles/files/ninutabopo.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607a0a1b96dcc---9114729410.pdfIn PDF document text
    • http://dierenwinkelindex.nl/images/uploads/71657327100.pdfIn PDF document text
    • http://prospekt-rostov.ru/ckfinder/userfiles/files/wusazibekakojovanewadolu.pdfIn PDF document text
    • http://aquatrustfina.com/userfiles/file/rusuguxokekivikowimisugo.pdfIn PDF document text
    • http://faxik.ru/ckfinder/userfiles/files/gakasuwasojunuporokufe.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_off0000da61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA61 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f273.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF273 17452 bytes
SHA-256: 064b3a29b94425809f0fb9b3e6501082d5821e2e8d38a582c1a38f1f7238bd50
font_02_sfnt_off00011f33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F33 10668 bytes
SHA-256: 17661e9d3868173d65c56e07145d566b0baf9b0a382425d9a474def8770ff58e