Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9f13716ee1b43ff…

MALICIOUS

PDF

81.5 KB Created: 2021-09-18 18:54:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2b5d1ccb8b9f255a9151602511faad42 SHA-1: 4616cc4e3b2f3bf3d84545d227f4b140a2d539f0 SHA-256: a9f13716ee1b43ff6efbd38740bc222b410bada20a891c30493fe9e22065354a
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, many of which are hosted on disposable domains or compromised CMS uploads. The URLs extracted are likely part of a campaign to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 http://huanghels.com/filespath/files/20210902001422.pdf In PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613dfb6923c01---wugezirimoz.pdfIn PDF document text
    • http://bebsulmare.com/userfiles/files/jowiwibopo.pdfIn PDF document text
    • https://www.mediawerf.nl/bundles/store24backoffice/ckfinder/userfiles/files/zovizobol.pdfIn PDF document text
    • http://old.bgk-meshkova.com/ckeditor/ckfinder/userfiles/files/55834351045.pdfIn PDF document text
    • https://banderlogclub.ru/Files/file/sapupukujogikebip.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/1018817716.pdfIn PDF document text
    • https://epponline.com/mentorfinancial/page_images/file/dofumumuxiligexutejo.pdfIn PDF document text
    • https://nirmalujjwal.com/public/ckfinder/userfiles/files/98119035306.pdfIn PDF document text
    • https://mintedimages.com/ckfinder/userfiles/files/paponifobikawibojojo.pdfIn PDF document text
    • https://makojudo.pl/zdjecia/fck/file/89945457766.pdfIn PDF document text
    • http://schokoladenbrunnen.de/idata/bijokuralawinuvitiluw.pdfIn PDF document text
    • http://technoprofile.ru/userfiles/file/vuguwe.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/xavewoxojajebujanaz.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16144d84ce35a8---2593987184.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf1bb93f66---demakugekadojekawux.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/pse0r9jnhp6lffjg24kovo95o4/gojof.pdfIn PDF document text
    • http://metapolar.hu/tmp/riwadunixetijinapa.pdfIn PDF document text
    • https://mobilpetrol.olajpark.hu/files/files/58995898758.pdfIn PDF document text
    • http://cesishotel.com/res/wysiwyg/file/zuxaxiwijuki.pdfIn PDF document text
    • http://farmaciafoglia.eu/userfiles/files/suxufe.pdfIn PDF document text
    • http://moriefrusca.com/userfiles/files/8842655428.pdfIn PDF document text
    • http://slstudio.it/userfiles/files/kamalojezaxu.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/nalafal.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=android+windows+screen+mirroringPDF 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_off0000dbec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBEC 10476 bytes
SHA-256: d525ce25ab2149be56e1aef3669f3ba00e2052bb0c90830b915988291b93913f
font_01_sfnt_off0000f387.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF387 17464 bytes
SHA-256: 57833e567d0a09f702dd8e9a4fcd5f0f09645c561c78f2cee611b5011038ea4a
font_02_sfnt_off0001208d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1208D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1