Malicious PDF — malware analysis report

Static analysis result for SHA-256 b237555e914c4d91…

MALICIOUS

PDF

67.8 KB Created: 2021-09-08 05:53:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e28e534fa18790471d6efa42c6bc461b SHA-1: 00d1916e1597d169a477a6e101cebf5a4ea6a26a SHA-256: b237555e914c4d91a10576ffa191540930dea7e9ea71e1314774108d865d55b6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URI heuristics and the nature of the URLs indicate a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7610

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://accronline.com/userfiles/file/sumux.pdf In PDF document text
    • https://home-consult.lu/userfiles/files/12390669566.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160881bbe15653---73443898903.pdfIn PDF document text
    • https://agermag.ro/mm/file/97978163605.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086d7b6255ac---gogexalomonawemofowos.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/49352598.pdfIn PDF document text
    • http://tano-cable.com/d/files/dikejibekisaxisiga.pdfIn PDF document text
    • http://zpb-maciejewski.pl/upload/fck/file/loreviz.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160beb917b6869---wokebagubiwobokojida.pdfIn PDF document text
    • http://santabruna.cl/upload/file/pabokuvosenujazamixigur.pdfIn PDF document text
    • https://clubelsendero.com/img_pag/file/28208806048.pdfIn PDF document text
    • http://bakkervoorwinde.nl/app/webroot/files/ckeditor_files/files/80939813078.pdfIn PDF document text
    • http://philipwillettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/93949590327.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/f5c8ed6b143a88cd3fd4efd778c9e319/84099561084.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/16094a9c9baa06---lavedatatafilavupelude.pdfIn PDF document text
    • https://altinhediyeler.com/calisma2/files/uploads/83276136503.pdfIn PDF document text
    • https://worldmedglobal.com/userfiles/files/bexuvudo.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/hmau128elfj4be2d06pkb9t8v4/13611425539.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a4b3f13d683---86430859903.pdfIn PDF document text
    • http://kidneytexas.org/clients/861060/File/70529289061.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/ec1146fd3185e0313195ea38b42bd80b/mavarozejot.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085c4dc96f9c---wajijefawutanuwefav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=cell+parts+and+their+functions+pdfPDF link annotation
    • 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_off0000b7a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7A5 15064 bytes
SHA-256: 4d0f974d6645c4d5bc76dacfa2e147cccf7435f723c8ce2c6940691abec67a5d
font_01_sfnt_off0000dd8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD8E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f5a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A5 10848 bytes
SHA-256: b7ee7a05034152538d6cfbe42a8b2f5d8627d500c73773d66e29de86029aeb9f