Malicious PDF — malware analysis report

Static analysis result for SHA-256 98c701830310aa11…

MALICIOUS

PDF

80.9 KB Created: 2021-09-16 11:49:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 10c9e2d4183b7b0a1e56e9a679912589 SHA-1: 438f8830fcdead19cfb5eab78e4c8b9710e3ae75 SHA-256: 98c701830310aa112d04f8887ddc5c7acf2a783ee191398954efab52257f3904
96 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous external URLs, many pointing to PDF files hosted on various domains. Heuristics indicate these are likely compromised CMS uploads or disposable hosting, suggesting a malicious intent to distribute content or manipulate search results. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://ciiinnovationsummit.com/ci/userfiles/files/50268898675.pdf In PDF document text
    • http://immobilieninvestors.de/userfiles/file/53746270404.pdfIn PDF document text
    • https://medarbindia.org/ckfinder/userfiles/files/43314701377.pdfIn PDF document text
    • http://chretkinia.pl/userfiles/file/92524516691.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161406955490e8---gelulisules.pdfIn PDF document text
    • https://md-bud.pl/szklo/photos/file/lisaganawiwijupewakozabep.pdfIn PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/kudonojuwinujunetinina.pdfIn PDF document text
    • http://www.specemc.ru/upload/files/51042210611.pdfIn PDF document text
    • http://www.dawnrotaryclub.tw/UserFiles/files/bunega.pdfIn PDF document text
    • https://33mobility.net/uploads/files/31805135066.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b1b6a7eebd---vojasavopibi.pdfIn PDF document text
    • http://abcbyspu.com/ckfinder/images_store/files/solazatowakawakasuwilu.pdfIn PDF document text
    • https://jsptti.com/ckeditor/ckfinder/userfiles/files/wabadej.pdfIn PDF document text
    • http://dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/kabapu.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e2b8d3d2f---sefetofalolagowof.pdfIn PDF document text
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/67574681827.pdfIn PDF document text
    • http://fusiongrup.ro/userfiles/file/86653432020.pdfIn PDF document text
    • http://florylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/45021024763.pdfIn PDF document text
    • http://yingtailong.com/upload/file/210916071732297115c4xp1t7i8z89.pdfIn PDF document text
    • http://parikshitconstruction.com/uploads/puwejaboni.pdfIn PDF document text
    • http://myphammonly.com/luutru/files/pabetowimotuxaj.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/35794278636.pdfIn PDF document text
    • http://pinxedien.net/upload/files/94044916680.pdfIn PDF document text
    • https://unitedfightalliance.com/ckfinder/userfiles/files/vufawetebegaxevoreni.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1631342734.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=android+9+call+forwardingPDF link annotation
    • 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_off0000d955.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD955 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f167.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF167 17028 bytes
SHA-256: 2177c00383289a16c6f57edd344e844f407af80ff8aaad385d9d73daf964b72c
font_02_sfnt_off00011dda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DDA 10488 bytes
SHA-256: fb1217ddd4df3903bc16ee80aa9611fd814795ef03998e5025242ded6c6379c2