Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b64c33c7f90a643…

MALICIOUS

PDF

93.1 KB Created: 2021-09-16 04:27:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 0dc7ff78f20c21f499530dd571eeb67d SHA-1: 3e513abdd923005181b788e7001ab3b5a5693aed SHA-256: 3b64c33c7f90a643fc98f21618ed7e9baccd130c57d963b6b6b4735170cc22df
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document contains numerous links pointing to disposable domains, suggesting a phishing or malware distribution scheme. The embedded URLs and the structure of the document strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • 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.
  • 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.ih-consultant.com/ckfinder/userfiles/files/madutakoze.pdf In PDF document text
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/36514716212.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/vebeguxa.pdfIn PDF document text
    • http://archinfo.ru/uploads/file/98113405747.pdfIn PDF document text
    • http://x-mobio.com/upload/files/67808364782.pdfIn PDF document text
    • http://xszhuhai.com/uploadfiles/files/netotuvepinumetowupe.pdfIn PDF document text
    • https://optical-axis.com/uploads/files/202109151837034657.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/67192306345.pdfIn PDF document text
    • https://thic.net/plugin/ce1/ckfinder/userfiles/files/guzitipebeno.pdfIn PDF document text
    • http://lhdrum.com/User_File/UpFile/file/20210912033100_MTE3Mjg2NzUyOTE=.pdfIn PDF document text
    • http://life-homeshop.com/asset/uploads/files/48626303741.pdfIn PDF document text
    • http://bluestandard.pl/ckfinder/userfiles/files/gimonub.pdfIn PDF document text
    • http://africalegal.nl/userfiles/file/duwusirovefumimavuj.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613db0e0dfb6b---45460848422.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1613d79bd6bba4---74117505529.pdfIn PDF document text
    • http://sakesushilakehavasu.com/uploads/files/wugulerus.pdfIn PDF document text
    • http://xahscw.com/userfiles/file/wakajefawutirurubu.pdfIn PDF document text
    • https://liho.cz/UserFiles/File/tonoxenogasesisuzoze.pdfIn PDF document text
    • http://www.drivingschool-brno.cz/files/files/28209539110.pdfIn PDF document text
    • http://filipdegreef.be/uploads/files/71148371069.pdfIn PDF document text
    • https://gjbuyerbroker.com/userfiles/file/44511713947.pdfIn PDF document text
    • https://y3stwk65l-mn9.com/contents/files/wuvusexifumubekow.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/tmp/vofinivo.pdfIn PDF document text
    • http://ryyw.com/upload/files/2021/09/202109140009204843.pdfIn PDF document text
    • http://saga.diamonds/uploads/ckfinder/files/zezibova.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=now+you+see+me+castPDF 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_off00010548.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10548 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011d5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D5F 10324 bytes
SHA-256: 1457d552e285787955dd89e4f00c88c6997d82606519aaca0be90785ce631ef5
font_02_sfnt_off000134dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134DC 19340 bytes
SHA-256: 218cd9189806c28aeaf3732933255429386c9da868a12b128da9a98cbda6fbe0