Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bf43e55bedec6c6…

MALICIOUS

PDF

68.3 KB Created: 2021-09-28 17:03:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 070e9ed0959afff71d3b7fd98baf9947 SHA-1: 8cd93ad61cd686d07efa2bb61b3d394c7b9aa254 SHA-256: 8bf43e55bedec6c6d95d49b32607d5c172f170a6a6e57b1576dedae17977a105
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous URLs, many of which point to link farms on disposable hosting or compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery through these links. The embedded JavaScript is a common technique for executing malicious actions within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://crewmak.ru/uplcv?utm_term=best+messages+app+android PDF link annotation
    • https://kudamatsu.org/userfiles/file/pubakotapeme.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/gediwotafov.pdfIn PDF document text
    • http://highspiritsmusic.com/ckfinder/userfiles/files/25153873137.pdfIn PDF document text
    • https://titishop.co/upload/files/gesikeve.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/opp0195sb6670r63ad28d7pvc4/95526581988.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/6180522514.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/xatituxejijavo.pdfIn PDF document text
    • http://starfishdowney.com/uploads/files/37480825466.pdfIn PDF document text
    • http://icmasistemas.com/userfiles/files/45030086618.pdfIn PDF document text
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/41914609056.pdfIn PDF document text
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/sololatewezel.pdfIn PDF document text
    • http://honda-vo.com/upload/file/baxatepit.pdfIn PDF document text
    • http://ticketsperiodico.com/galeria/files/zikidawarasewasekumoxiri.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/60a942c30a3b47c30967df05a2eb141d/23670890564.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/ece4487eeed5ca94c74eebce602c6fa0/loragala.pdfIn PDF document text
    • http://riph.pl/userfiles/file/lomebe.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/bogotutol.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613573902bf4d---jorewi.pdfIn PDF document text
    • http://idominjazz.com/fckeditor/userfiles/image/vilopiredowawov.pdfIn PDF document text
    • http://nickelsgrafikdesign.de/ckfinder/userfiles/files/vufedipis.pdfIn PDF document text
    • http://sichera.eu/userfiles/files/lebebadipevipojudebijewa.pdfIn PDF document text
    • https://jeanmarcrobion.fr/userfiles/file/pukoxefurubege.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_off0000ad62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD62 15164 bytes
SHA-256: 02555c4429d2fb3e769d5f7e0f36055c544699ff0e3be4d99765cc600be1e7e7
font_01_sfnt_off0000d324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD324 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eb3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB3B 10740 bytes
SHA-256: be4cbd7416ec190611f1e7cda67f6e6b67a22ad090600efdf1e1a6b80ff38120