Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3c4b349a936b740…

MALICIOUS

PDF

82.3 KB Created: 2021-09-24 07:25:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 54c786d6ea58e0eaa99ed5ac3b74914c SHA-1: 840d520865be991f3e0df3a6b54225e8fb508ac8 SHA-256: c3c4b349a936b7408c7b6fdd9ead24c1c473bb462873a829b731d4116b4848c6
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. Several heuristics indicate the PDF is part of a link farm, pointing to external URLs hosted on potentially compromised websites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.ez4parcel.net/upfile/files/2021/09/08/miwiniguxefosexowodud.pdf In PDF document text
    • https://www.travelknowhowscotland.co.uk/assets/js/ckfinder/userfiles/files/75477829909.pdfIn PDF document text
    • http://cicm2015.mist.ac.bd/app/webroot/ckfinder/userfiles/files/28284661633.pdfIn PDF document text
    • https://coolinterier.sk/upload/files/zexamofexazesedafarafi.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d24a4643f7---noxepuvogepedire.pdfIn PDF document text
    • http://xhslsh.gdx.cn/ckfinder/userfiles/files/fuduvubixuzajetokadutaxif.pdfIn PDF document text
    • http://abwwilson.com/uploads/files/gedagiladesuvufesen.pdfIn PDF document text
    • https://e-casainteligenta.ro/userfiles/file/wufojaxolirazumurozubisos.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614d3d8b212d4---67507113270.pdfIn PDF document text
    • http://szybkieprawko.pl/szybkieprawko.pl/user/admin/fck/file/suzotirofitototuxinux.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613cc2132992d---45739457154.pdfIn PDF document text
    • http://sz-frp.com/pic/20210920201827516.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/f797ab10674398ea718da3b568b52325/15083816691.pdfIn PDF document text
    • https://aymexco.ro/ckfinder/userfiles/files/nugazamisevubo.pdfIn PDF document text
    • http://gurgaontaxi.com/pa/trainstation/uploads/image/file/kotilanolefamejev.pdfIn PDF document text
    • http://sincaremedicaltour.com/js/upload/59005428823.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/8688cb154df8f4e54c4e4b119fea7415/60378652032.pdfIn PDF document text
    • http://gdlejia.com/uploadfile/files/20210909_052322.pdfIn PDF document text
    • http://zzzwchem.com/upload/files/nenefumegozatemup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=el+mundo+amarillo+pdfPDF 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_off0000da4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA4C 10344 bytes
SHA-256: 166cf490373d5127878c05776d9a4c184ca7f302b6d5fb8dccef2a7ce0c71a45
font_01_sfnt_off0000f16d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF16D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001097f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1097F 19588 bytes
SHA-256: f56a7c1b76baab140ed80d670103914d12582080a0f6edafe7d235b991465813