Malicious PDF — malware analysis report

Static analysis result for SHA-256 af6a6707a158366c…

MALICIOUS

PDF

84.6 KB Created: 2021-09-14 08:55:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 913eacb70c7657cbc10dc145e32efc96 SHA-1: 571e3d46c2c0039e26f55064976fca7c2447a8d5 SHA-256: af6a6707a158366c967d73fa9cddd8eb5da341310fe735648bbf0237ae023853
156 Risk Score

Malware Insights

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

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users. The presence of UTM parameters in one URL indicates a potential phishing or tracking campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://coretry.ru/uplcv?utm_term=if+i+switch+from+iphone+to+android PDF link annotation
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613a65ccf3b2c---mufetazawikug.pdfIn PDF document text
    • http://xnucleus.com/members/member_images/files/55748334384.pdfIn PDF document text
    • http://gbfrjournal.org/pds/userfiles/files/tolexarakedezumisejufo.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/neworafuwutedomoni.pdfIn PDF document text
    • http://videocycling.info/files/file/63868294301.pdfIn PDF document text
    • https://fu-ko-property-agency.com/webroot/editor-uploads/files/nukomudikinepu.pdfIn PDF document text
    • http://zamel2.pl/userfiles/file/46316756787.pdfIn PDF document text
    • https://jiu-hang.com/upfiles/editor/files/vewex.pdfIn PDF document text
    • http://pyroglobal.sk/app/webroot/files/userfiles/files/40185791703.pdfIn PDF document text
    • https://danielfelber.ch/userfiles/file/12692430951.pdfIn PDF document text
    • https://mudrun.com/home/mud/public_html/ckfinder/userfiles/files/wefir.pdfIn PDF document text
    • http://baloneacessorios.com/_upload/file///kirafeg.pdfIn PDF document text
    • http://favourtec.com/attachment/file/78925702745.pdfIn PDF document text
    • http://sicilyontable.it/userfiles/files/56511504807.pdfIn PDF document text
    • http://clubesquilacoma.com/uploads/files/94056103465.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaf719c9e4---32809678874.pdfIn PDF document text
    • http://hoteldanang.vn/uploads/images/files/sodisoxa.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/97798fc83a074fe45af0f6e8e5b848ce/60213637052.pdfIn PDF document text
    • http://asclyziarskyklub.sk/userfiles/file/zuzizaz.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16136e2dcc0460---8158261759.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/2e8809fa7e7c9ceb4fc10781d99aa9c3/56052783733.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/73367201497.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/b79f880e34f8eb5f274d3ba58f5d7428/livadubutijuf.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_off0000e774.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE774 17104 bytes
SHA-256: f274d5847b48c918bfe0abe7f070d0adf5849d113e8c7b5e42097283a35bebdc
font_01_sfnt_off0001136d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1136D 10876 bytes
SHA-256: b12f35cfa4fb46f954bfb4d49f48e119f2eb349a917537aea7572551186dc310
font_02_sfnt_off00012c72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C72 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1