Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8b5129eacc40003…

MALICIOUS

PDF

81.2 KB Created: 2021-09-12 01:01:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: fe5cfa487e598f1a60f336f8d8df3dd0 SHA-1: a12491ec9749a83e3ef9e047cec779bd0f80bb2e SHA-256: e8b5129eacc40003b1254e947852927658356bbb7893860055aed74c8ef30749
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous embedded URLs pointing to various domains, likely to obscure the ultimate destination or spread malicious content across multiple sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically identifies this pattern of using many distinct, low-link-count hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://korean-school.hu/hangul/userfiles/file/tujejibuwizepu.pdf In PDF document text
    • http://cgl.lu/userfiles/files/vamukenuvilis.pdfIn PDF document text
    • http://wangguanhardware.com/userfiles/file/vinovenar.pdfIn PDF document text
    • http://skupka23.ru/upload/m/pilomufarulisobupope.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133e898550a2---23217128633.pdfIn PDF document text
    • http://xn--dlek-5qa.com/admin/UserFiles/file/86975091235.pdfIn PDF document text
    • http://chinawin-consult.com/userfiles/38043989175.pdfIn PDF document text
    • http://artecgroupservices.com/imagenes/file/65813988886.pdfIn PDF document text
    • http://brilspa.ro/userfiles/file///50667003761.pdfIn PDF document text
    • https://funke.be/data/file/nogebi.pdfIn PDF document text
    • http://dungcumaymoc.com/Images_upload/files/gevogozopisogu.pdfIn PDF document text
    • http://ohdiabo.net/images/ckeditor/files/61791152781.pdfIn PDF document text
    • http://www.kyousei-fukushi.or.jp/system/ckfinder/userfiles/files/85989915650.pdfIn PDF document text
    • http://candientu24h.vn/webroot/img/files/xikikokizi.pdfIn PDF document text
    • http://cameradungphat.com/uploads/files/9525267362.pdfIn PDF document text
    • https://taxfirma.com/userfiles/file/xevatamonogogajedowevavi.pdfIn PDF document text
    • http://ieeepes-thailand.org/app/webroot/files/files/91770351887.pdfIn PDF document text
    • http://szerecsengyogyszertar.hu/editor_up/78637569852.pdfIn PDF document text
    • http://tortsurprise.ru/upload/redactor/files/36906650432.pdfIn PDF document text
    • https://globalmediaminds.com/uploads/files/narupenefe.pdfIn PDF document text
    • https://bodymart.in/ckfinder/userfiles/files/wopiwofakojawogatemoxo.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16138fa2e8f56e---90139554661.pdfIn PDF document text
    • http://ropesadventure.com/d/files/69795830263.pdfIn PDF document text
    • http://mega.kz/media/upload/files/9496569554.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=simple+and+compound+interest+practice+worksheet+answersPDF 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_off0000d919.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD919 17096 bytes
SHA-256: df6c30dc596276a912ae6e5d16493595c3ddfc3831490797dbc8b5cf6b52dcae
font_01_sfnt_off00010545.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10545 11132 bytes
SHA-256: e476d830dc652dc3e56b437983055408dcce9feb29fe4db9d56029fdee4366dc
font_02_sfnt_off00011f14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1