Malicious PDF — malware analysis report

Static analysis result for SHA-256 8398807ce2d01ef8…

MALICIOUS

PDF

76.8 KB Created: 2021-10-11 14:44:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: b9f22731911ca3dad47783862b06ba92 SHA-1: d2a5468f6320ac6f15c52f43a5b848847b50d9d5 SHA-256: 8398807ce2d01ef8bf4c60005526923fd182985c9f68bbce8b0d9527888eb81e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing embedded JavaScript, which is a common technique for malicious documents. Heuristics indicate it is part of a link farm pointing to compromised upload storage, suggesting an attempt to redirect users to malicious content. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://indian-sped.szabgab.hu/fck_uploads/pdf/80993052232.pdf In PDF document text
    • http://www.hro.ait.ac.th/js/ckfinder/userfiles/files/biwutonopifeno.pdfIn PDF document text
    • http://seattledesis.com/fckeditor/file/ruwodipinosego.pdfIn PDF document text
    • https://ags-car.com/upload/files/xajutaparul.pdfIn PDF document text
    • http://avemkz.internet-match.com/upload/files/mebadaxudenu.pdfIn PDF document text
    • https://coastalholidayproperty.com/ckfinder/userfiles/files/wewonotepexe.pdfIn PDF document text
    • http://ingatlantv.tv/userfiles/files/jewaso.pdfIn PDF document text
    • http://changjiujz.com/uploads/files/202109280838024853.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133f2cac0c05---bexobugoposixogovamuwapu.pdfIn PDF document text
    • http://theonejsc.com/userfiles/file/90858293042.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/57127800710.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/4a6595fc1d7326c57bccc03efb78ad67/vivirosowekowiwajorerod.pdfIn PDF document text
    • http://lso-msm.com/userfiles/file/jawegefaduxoj.pdfIn PDF document text
    • http://cataga.de/beta/files/file/fetuxopuba.pdfIn PDF document text
    • https://euroialinsol.ro/userfiles/file/kisutebibawezal.pdfIn PDF document text
    • http://dienhoabacninh.vn/webroot/img/files/lonobekuraxibuwubenopexe.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/63973422085.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/lutuzewu.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/23952823360.pdfIn PDF document text
    • http://xn--80ab1a9a.xn--p1ai/sadm_files/92543980576.pdfIn PDF document text
    • http://hotelrealerimini.it/userfiles/files/xuxebamoredobugimej.pdfIn PDF document text
    • http://autoescuelatosal.com/galeria/files/96839849228.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/16152f5fb09d76---9048137666.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/u-9XGpgKpwY/uplcv?utm_term=5+types+of+contraceptionPDF 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_off0000c867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC867 10576 bytes
SHA-256: ccec3b0d8b25b827fd04a7e9fe3da5cbb4c228a30ef4e0e02f6f3e8951a5b4ea
font_01_sfnt_off0000e0c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f8d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D7 17444 bytes
SHA-256: 114e782db15730ed1d6106875ca1b7b7f5f485ea03acef594d1210fb7e93a409