Malicious PDF — malware analysis report

Static analysis result for SHA-256 e54b5e631d065dd4…

MALICIOUS

PDF

74.0 KB Created: 2021-09-19 11:25:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9399afa43ae96409faae2319b3361016 SHA-1: 77ec60dc95e8b23f746803b484c67f5882cb185e SHA-256: e54b5e631d065dd41add9733fda2305c6df5e45176cb4ca08fd1fea91e1a519a
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, many pointing to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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
  • 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 http://architettotoma.it/userfiles/files/69377579642.pdf In PDF document text
    • http://cn-junsheng.com/upload/file///202196145783668.pdfIn PDF document text
    • http://xaydungphongphu.com/uploads/files/rimonapusuxalexo.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/9701110274.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/82226720794.pdfIn PDF document text
    • http://efrex.cz/files/file/46143913599.pdfIn PDF document text
    • https://rajatotogroup4.com/contents/files/45899413496.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/69094806476.pdfIn PDF document text
    • http://pickup-ws.com/userfiles/files/67087414578.pdfIn PDF document text
    • http://worldtile.net/jangheung/userfiles/file/degez.pdfIn PDF document text
    • http://jiab.net/userData/board/file/42369770270.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/19218990715.pdfIn PDF document text
    • http://liceoadultos.juniorcollege.cl/userfiles/files/sinumekotagagusedana.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee3258df8a---62422602591.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/16145967d5cd50---35824137636.pdfIn PDF document text
    • https://travelone.ae/userfiles/files/xolugenulufegab.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16136d48ec5c4b---kedasenaxevem.pdfIn PDF document text
    • http://caudafotografia.com/userfiles/files/rojat.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.com/filespath/files/20210915161157.pdfIn PDF document text
    • http://eviljoy.com/UserFiles/File/kifenitiz.pdfIn PDF document text
    • http://khachsansapa.vn/webroot/img/files/80352932557.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16130efd78a021---86984756079.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/wamomipefuv.pdfIn PDF document text
    • http://elistaprezentow.pl/userfiles/file/17712829770.pdfIn PDF document text
    • http://retco.ge/ckfinder/userfiles/files/51244633965.pdfIn PDF document text
    • http://itcck.org/upload/editor/file/90441954837.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613a677a307ec---mikemojuwi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=the+littlest+penguin+3dPDF 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_off0000bf75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF75 10524 bytes
SHA-256: d1dcaca2ae0cb406f8bd9ddf2765113ba14d79fd696912a69fe1ea02136fc8ca
font_01_sfnt_off0000d72b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD72B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF3D 16708 bytes
SHA-256: 1d0d301e517215c9a92d7bd07f3532543a5a4de9274fad0326e68795369ae44a