Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d51af0e68035b77…

MALICIOUS

PDF

86.0 KB Created: 2021-09-09 10:58:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 2a81cd21bb27dd7b051a5882230d586a SHA-1: a1a480094ab6e792001282c71b4c2e3914c4c7cd SHA-256: 4d51af0e68035b774510fd58af72a648da184e306d8a0c47849cba6505845339
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, suggesting a link farm designed to redirect users to malicious content. The ML classifier strongly indicated maliciousness, and the presence of multiple PDF link farm heuristics supports this assessment. No scripts were extracted, but the overall structure points to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://pistant.ru/uplcv?utm_term=gta+mobile+games+free+download PDF link annotation
    • http://globalcenterhotels.com/bot/ckfinder/uf/files/62075721419.pdfIn PDF document text
    • https://digireg.cn/upload/69069889266.pdfIn PDF document text
    • https://mmoxx.mn/userfiles/files/jikokibugovatikijowi.pdfIn PDF document text
    • https://bokaichenyu.com/upload/files/jewave.pdfIn PDF document text
    • https://clove7.com/userfiles/file/61303219490.pdfIn PDF document text
    • http://mikllc.mn/uploads/files/61573595411.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/1955d75b3edfa183068b92491dd09fa2/dusoturujivuloveto.pdfIn PDF document text
    • http://ccadl.com/files/20210907065523.pdfIn PDF document text
    • https://mimpiindah168.com/contents/files/54155408023.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/kapatogafepu.pdfIn PDF document text
    • http://hoangnampte.vn/quangbasanpham/app/webroot/upload/image/files/dolil.pdfIn PDF document text
    • http://somkuthyoptika.hu/editor_up/rexas.pdfIn PDF document text
    • http://www.iuoelocal870.com/kaizen/ckfinder/userfiles/files/jorovifejaxisat.pdfIn PDF document text
    • https://clinicaabrahaoosta.com.br/ckfinder/userfiles/files/ninofozivamidafo.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/77cd7d6a591a7a978da7a6e538fe523e/zarujibel.pdfIn PDF document text
    • https://mcq.bmtinhoc.vn/InteriorWeb/images/images_news/files/sudobujemaxiti.pdfIn PDF document text
    • http://corporatiegids.nl/uploads/files/84502426257.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136cbfe227ac---fifegibekodojuri.pdfIn PDF document text
    • http://www.atccs3.it/atccs3/fckeditor/editor/ckfinder/userfiles/files/9761863661.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/161392b53a8bb5---tudugadox.pdfIn PDF document text
    • http://xn--b1agpbmdtf.xn--p1ai/upload/file/rebenevosadetojulajisa.pdfIn PDF document text
    • https://unovosti.tv/ckfinder/userfiles/files/89877566004.pdfIn PDF document text
    • https://agmatbaa.com/upload/files/tugonilosoraxa.pdfIn PDF document text
    • http://atek-ent.com/upload/file/fozotewuxatukelafedagoz.pdfIn PDF document text
    • https://varida-tech.com/ckfinder/userfiles/files/voxedumisisivotef.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_off0000e785.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE785 18836 bytes
SHA-256: 1e2afa756cd7788b4098302af3719813fbb25f1dae0f88786130c313c6d6fa70
font_01_sfnt_off000118a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118A4 10964 bytes
SHA-256: 83b49fa1aac08c58f19f0caa4b10e25952b971c9ee74de14be1623d91dd36fff
font_02_sfnt_off000131ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1