Malicious PDF — malware analysis report

Static analysis result for SHA-256 36091c87fe83c2c2…

MALICIOUS

PDF

70.4 KB Created: 2021-09-27 06:32:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6976f89a067e12603bbad79d0f3d39c8 SHA-1: 760f08ed2536ef0a81b884e599a978e95772b9ab SHA-256: 36091c87fe83c2c2263f66f61ee6d336ca8aa83745362818d8000ffb86877643
156 Risk Score

Malware Insights

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

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 upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these links and the overall structure strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://smidgel.ru/uplcv?utm_term=advantages+and+disadvantages+of+stem+cells PDF link annotation
    • https://weilaimachinery.com/userfiles/files/14120682305.pdfIn PDF document text
    • https://sofahatinh.com/upload/files/84003104023.pdfIn PDF document text
    • http://stylekd.ru/files/3504796231.pdfIn PDF document text
    • http://duda-tech.pl/dudatech/upload/file/69930985839.pdfIn PDF document text
    • http://studiofranzoni.eu/userfiles/files/kewuxurunudanavofivako.pdfIn PDF document text
    • http://rockefellersgold.hu/editor_up/13083088747.pdfIn PDF document text
    • http://aranysolyomfeszke.hu/editor_up/kilovon.pdfIn PDF document text
    • http://jmlukanich.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pojuzexi.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e686c78f19---viniziposevabifadewusopod.pdfIn PDF document text
    • http://spec-so.ru/sites/default/files/file/62093931904.pdfIn PDF document text
    • http://arc-en-cielproduce.com/ckfinder/userfiles/files/30574797279.pdfIn PDF document text
    • http://seoulmenu.com/uploads/files/25382839777.pdfIn PDF document text
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/53304774675.pdfIn PDF document text
    • http://zbigniewrodak.pl/galeria/file/52738003556.pdfIn PDF document text
    • http://se-ty.com/uploads/userfiles/file/zuwun.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c2c011f5b7---14996350392.pdfIn PDF document text
    • https://www.assofmt.org/ckfinder/userfiles/files/xefuresikadonu.pdfIn PDF document text
    • http://boki.hu/editor_up/49650020517.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd67973935---28526237225.pdfIn PDF document text
    • https://pakianco.ir/data/image/uploads/news/files/tasunova.pdfIn PDF document text
    • https://comfortinnbarrie.com/phpsites/vertical_living/uploads/file/19422152911.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_off0000b152.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB152 16792 bytes
font_01_sfnt_off0000c969.bin
f72ee123d31e24d33ae809f99e1a07cc73cea683eb528f35bd757d7e8a48eced
pdf-font-stream PDF embedded font (sfnt) at offset 0xC969 10764 bytes
font_02_sfnt_off0000e20a.bin
19f92e0e676bfd562187519423f6f94e3485ee776adca1215860e3d94658d43e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE20A 16480 bytes