Malicious PDF — malware analysis report

Static analysis result for SHA-256 9cb50dd70796ab37…

MALICIOUS

PDF

84.8 KB Created: 2021-09-09 16:26:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 083f0a587e9e77c68e7a9008a7e02a4d SHA-1: 88a9663e22554ce6073bdba3a2ba469139ccf851 SHA-256: 9cb50dd70796ab37211f5c9e6ca77652b03978914c7dc70208d5bba42c91d593
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or SEO manipulation. The embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirm the nature of the document as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://gagiongvitgiong.com/ckfinder/userfiles/files/32852086237.pdf In PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/16135bfd643034---surasulunikifexaredipa.pdfIn PDF document text
    • https://www.delaneyllc.com/ckfinder/userfiles/files/41014927614.pdfIn PDF document text
    • http://d-innovation.com/upload/files/fobajizul.pdfIn PDF document text
    • http://yey.uw52.com/upload/files/goketogokiv.pdfIn PDF document text
    • http://saipanbooking.com/FileData/ckfinder/files/20210908_2BDB32F885D26408.pdfIn PDF document text
    • https://horgaszvelem.hu/ckfinder/userfiles/files/44043583475.pdfIn PDF document text
    • http://larrysiegellaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/21163826357.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/c6f347afcd6291cac473320a31e4f5d9/14349958654.pdfIn PDF document text
    • http://lab4050.com/upload/editor/file/vidutuwebuva.pdfIn PDF document text
    • http://hart-metale.pl/gimnazjum/userfiles/file/megivebajuxafedofi.pdfIn PDF document text
    • http://gucaoyun.com/uploads/file/062225284217.pdfIn PDF document text
    • http://olsztyntransportmedyczny.pl/userfiles/file/39991992251.pdfIn PDF document text
    • https://fasleh.net/Files/files/55692184686.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/73161400648.pdfIn PDF document text
    • http://www.herbertvanderbrugghen.nl/draft/romovesavivevopakuzinepu.pdfIn PDF document text
    • https://beaszemin.com/files/sawulipatoturosi.pdfIn PDF document text
    • http://skisun.it/userfiles/files/zusofokawe.pdfIn PDF document text
    • http://sireny.net/share/files/korovijimesetek.pdfIn PDF document text
    • http://tomaszskiba.com/userfiles/file/wimopasetexepituvibupili.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee49c794de---figulotopod.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/trtjl5lv9mvdvalajh28viop17/lupabum.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/411bb1f923c466fb870ad4f4a85b800d/jovesep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=photography+apps+android+freePDF 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_off0000e582.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE582 10844 bytes
SHA-256: a61f9dfdf73334ddb7763b49d61ff2e2d5a72bd8e7f486c6b6b92013c8c4c787
font_01_sfnt_off0000fe5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001166f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1166F 18376 bytes
SHA-256: ffcc2cebe770338709a8bf6d0a06832c0fdd1ad84098812deae491469b22d15f