Malicious PDF — malware analysis report

Static analysis result for SHA-256 561347e5e5574ca0…

MALICIOUS

PDF

80.7 KB Created: 2021-10-06 23:37:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 229e17629e51a9b220ce2971575ce996 SHA-1: 92de7407af8e0c138b8e97c13882c63293a8180e SHA-256: 561347e5e5574ca01f3b6d8bff5d8c0b99439a6f0d1b536e857e26fb7ac1d78e
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous embedded URLs pointing to other PDF files hosted on various domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, suggesting an attempt to obscure the true malicious destination or evade detection. The primary attack pattern involves luring users to click on these links, likely leading to further malicious content or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://urparitet.ru/admin/ckfinder/userfiles/files/66839825663.pdf In PDF document text
    • http://sahcarpets.com/userfiles/file/tukanevubosolebuju.pdfIn PDF document text
    • http://manvilastrust-org.bvirani.com/ckfinder/userfiles/files/wuborogejewabunededixamu.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fa1bdd3513---23626942551.pdfIn PDF document text
    • http://biosurfest.com/userfiles/files/73600912979.pdfIn PDF document text
    • http://www.sana-anong.com/ckeditor/ckfinder/userfiles2/files/fopexaxonefope.pdfIn PDF document text
    • http://arkystudio.eu/userfiles/files/73914378234.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/zubabotodabozivada.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/21063842780.pdfIn PDF document text
    • https://akemi.ro/hirek/file/88072184913.pdfIn PDF document text
    • http://malabarisproducoes.com/arquivos/files/24224168879.pdfIn PDF document text
    • https://mldom.xyz/web/img/podborky/files/74567233194.pdfIn PDF document text
    • http://www.gyndoktors.de/ckfinder/userfiles/files/potojeximuvavadasakiw.pdfIn PDF document text
    • http://thoitranglani.com/upload/files/tutiledorazezokux.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/gisofejavuf.pdfIn PDF document text
    • https://kocgrafikavukatwebsitesi.demowebsiteleri.com/upload/files/fexewaxepomek.pdfIn PDF document text
    • https://hankilfood.com/upfile/files/56554772857.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/26436324753.pdfIn PDF document text
    • http://rund-sro.cz/UserFiles/File/81839194108.pdfIn PDF document text
    • https://jackinthegymtpe.com/uploads/files/202109092248596869.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1615dca25b02b1---15296944369.pdfIn PDF document text
    • https://dm288.rs/slicice/file/9804001074.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=human+rights+quiz+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_off0000d498.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD498 18892 bytes
SHA-256: 58d0e3093005a267189a744ca67f27a5db64fb7ef13a823a4014e29cc0adddf1
font_01_sfnt_off00010488.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10488 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C9F 10772 bytes
SHA-256: 9367415cda31fb3b57c7690cc1d0c2b7ec5a8d35cf61bfcb9fa653018e79d733