Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8dec0d3b6e1d3d8…

MALICIOUS

PDF

72.0 KB Created: 2021-09-29 08:02:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9dfce4383fae9cb0e020f984c8ee65e5 SHA-1: 23f49fbb9db670ca829c36353ebf4be46df022d6 SHA-256: a8dec0d3b6e1d3d83dedca85ec18591de2435a4697407e11df5d4e740d9d1483
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that form a link farm, pointing to compromised WordPress uploads and other disposable hosting sites. The primary function appears to be redirecting users to potentially malicious or phishing content, consistent with a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://inwebjor.ru/uplcv?utm_term=what+is+second+space+in+android PDF link annotation
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/a1deb0e4fd62497f49f894f527ad6548/wotibawojowajuke.pdfIn PDF document text
    • http://gzxmbx.com/uploadfile/file/2021092004220873499.pdfIn PDF document text
    • https://cnc-ar.ro/files/file/24686927548.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/31485963538.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/latumatumonebaf.pdfIn PDF document text
    • http://jmvlpslimited.com/ci/userfiles/files/41948392849.pdfIn PDF document text
    • https://renesens21.com/ressources/upload/files/87239598739.pdfIn PDF document text
    • http://geoman.cz/data/file/ruxuvezaxodinosog.pdfIn PDF document text
    • http://speckrepej.com/upload/file/67813438657.pdfIn PDF document text
    • https://austarpharma.com/upload/files/lopinebimuxuberifodux.pdfIn PDF document text
    • https://tranduongauto.com/app/webroot/files/images/pages/files/junirevijijazurexa.pdfIn PDF document text
    • http://thecuriosityshot.com/25532098305.pdfIn PDF document text
    • http://bioscipublisher.com/files/upfiles/file/61961724903.pdfIn PDF document text
    • http://mulroyenvironmental.ie/userfiles/file/82943783597.pdfIn PDF document text
    • https://www.sudicobank.com/ckfinder/userfiles/files/88530604375.pdfIn PDF document text
    • https://ldoris.com/upfile/files/20210907132952.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/09aed8755dd1649ad231c1d76ac96c3d/9854925792.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dbed7060ec---34805112103.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614dc26e4bc99---vofuluboresoz.pdfIn PDF document text
    • http://e-hematologica.com/users/file/pevafipo.pdfIn PDF document text
    • https://thuanxuongmonmb.com/admin/webroot/upload/image/files/3201272513.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_off0000b099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB099 10556 bytes
SHA-256: b3cf2812ec530548f6e773f2d809d5beb0e5f23958e50eb7a163475d121e7abb
font_01_sfnt_off0000c8a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e0bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BB 19584 bytes
SHA-256: 2ec6544fbca58fb3b81cb9ffe08cc066821fb20c8f435fd05c10889176e94ac3