Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8028a2f92410ff2…

MALICIOUS

PDF

71.3 KB Created: 2021-09-19 08:09:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: f851ef10379f1eea5b80bb632009d4d7 SHA-1: d4ef9c24f56acf0cac22335372ec51fc3f6e01e5 SHA-256: c8028a2f92410ff2332a9724eadac2ad9496a39e16881712ef37d1633357958a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ClamAV and an ML classifier, with high confidence. It contains embedded JavaScript and numerous external URIs, indicating it is designed to redirect users to potentially malicious websites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further suggests a link farm strategy, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • 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://cructi.ru/uplcv?utm_term=clash+royale+mod+apk+hack+download PDF link annotation
    • https://www.pelicanfinancialnetwork.com/ckfinder/userfiles/files/gukelur.pdfIn PDF document text
    • http://parzenica-bialka.pl/userfiles/files/sutixaj.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/wetugumorolitikifev.pdfIn PDF document text
    • http://tutek.eu/userfiles/file/zewekibupesewozanusenu.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf0e1afa0a---pujalazu.pdfIn PDF document text
    • http://nakamurasangyou.jp/app/webroot/uploads/files/rigofisefuxeravuneve.pdfIn PDF document text
    • http://medi-sen.com/files/files/28636681503.pdfIn PDF document text
    • http://www.clc-engineering.com/siteuploads/editorimg/file/49276743586.pdfIn PDF document text
    • https://giaynangchieucao.com/userfiles/file/rilubuzovokim.pdfIn PDF document text
    • https://pro-biomed.com/admin/userfiles/file/gapatefojosugoxuz.pdfIn PDF document text
    • https://brothers-music.com/ckfinder/userfiles/files/30943863540.pdfIn PDF document text
    • https://europacreativaeuskadi.eu/files/galeria/files/39104921097.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/56331147273.pdfIn PDF document text
    • http://myucpb.net/userfiles/file/5145987868.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613e9c4719c02---ditogubitiwapodipomu.pdfIn PDF document text
    • https://weilaimachinery.com/userfiles/files/vobapoxabamesaviso.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/xapoxedafajiri.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/dutis.pdfIn PDF document text
    • https://marbeyoyun.com/calisma2/files/uploads/zamunusibekimavemipiwo.pdfIn PDF document text
    • http://kliknetezde.cz/admin/obrazky/file/naxiniv.pdfIn PDF document text
    • https://copyjokertw.aw6.tw/uploadfile/qu4_qu106_com/files/97330618023.pdfIn PDF document text
    • http://aurora-c.jp/files/files/61710825290.pdfIn PDF document text
    • http://sunwisechem.com/Uploadfiles/files/zarivefejipilikux.pdfIn PDF document text
    • http://k-ookuma.com/js/upload/files/27645332042.pdfIn PDF document text
    • https://kme.pl/global/app/webroot/uploads/file/16306071471281.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_off0000b53d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB53D 10912 bytes
SHA-256: e93e2e0ece5ea2d651b9161b7c7542aa27174566b38b6361e61087acf96ef740
font_01_sfnt_off0000ce69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE69 16172 bytes
SHA-256: a52ba11d7f4d2382ea9a884bd258aa174852fa6fa65a80555541e44ba09e3635
font_02_sfnt_off0000f792.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF792 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1