Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd4ba6679a7e22d7…

MALICIOUS

PDF

71.1 KB Created: 2021-09-13 13:54:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4f50994481daba280afccc4fff516e10 SHA-1: fd6db15b665246ff2935f636416b1d541c6aeb66 SHA-256: bd4ba6679a7e22d7840e5ba7a664bfcd95421e93d0958f4811e6a601459baf9d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage and disposable hosting. This structure strongly suggests a link farm designed to distribute malicious content or facilitate phishing attacks. The ClamAV detection and ML classifier further support its malicious nature, indicating it is likely a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16136c8b15ac8e---75628258870.pdf In PDF document text
    • http://yogo110.com/userfiles/file/9657695334.pdfIn PDF document text
    • http://naitikfashions.com/ckfinder/userfiles/files/4478137149.pdfIn PDF document text
    • http://shanghaiqingchen.com/upload/files/49336651778.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/d8e4ca1e59477e1be67173c70f81794c/62463890490.pdfIn PDF document text
    • http://kamakuralosgatos.com/uploads/files/88051517595.pdfIn PDF document text
    • https://elitstroycraft.ru/source/file/sujubuwuwopubezenedas.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/bagiwebowawixa.pdfIn PDF document text
    • http://denki-shonan.com/uploadsfile/kosugokivuwizodapezane.pdfIn PDF document text
    • http://leeandrewdavison.com/download/tunakomirosabapavi.pdfIn PDF document text
    • https://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/teliro.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612faa8fb59be---tigitikozalegawut.pdfIn PDF document text
    • http://mijn-nederland.nl/userfiles/file/29552836872.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3490023c3---65121878646.pdfIn PDF document text
    • http://phanphoiongnhuahoasen.vn/upload/files/19349082621.pdfIn PDF document text
    • https://hfbee.tw/upload/ckfinder_temp/files/20210908153114.pdfIn PDF document text
    • http://toyteepee.com/uploadfiles/file/2109031030300592208zglgu.pdfIn PDF document text
    • https://ntct.dz/ckfinder/userfiles/files/78832504179.pdfIn PDF document text
    • https://ngusacdon.com/upload/files/niwewomuremenowojoxixax.pdfIn PDF document text
    • http://cnokorea.com/userfiles/file/bigigafavasozozene.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613763b148d70---kupakukizojejevezel.pdfIn PDF document text
    • https://hotelcorona.ro/files/15579181795.pdfIn PDF document text
    • http://hooleihomes.com/cms_images/file/47923050606.pdfIn PDF document text
    • http://alhambra.kopanramen.com/uploads/files/tagenoj.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb94929fac---41607819208.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=papercraft+animals+pdf+freePDF 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_off0000b717.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB717 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF29 15372 bytes
SHA-256: bfaa12fcdb01443db2f769ceff47c3df19b9d80f4d51376cf570af722a1c7644
font_02_sfnt_off0000f64e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF64E 10664 bytes
SHA-256: b44fc07405f32d5fdb0a70b36d9ca3ce1f26df63ad3bbe57d5b2d5ac749f31f4