Malicious PDF — malware analysis report

Static analysis result for SHA-256 661d0507ca3e9560…

MALICIOUS

PDF

83.1 KB Created: 2021-09-16 19:30:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d4ca0882997d0a7e5f5227ede057f6a7 SHA-1: d1096778df4f718c079feb38bfdc4fb998818a46 SHA-256: 661d0507ca3e956009bb4d6c67019c34845cf64750f7974911857a0447f62a71
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://inwebjor.ru/uplcv?utm_term=the+walking+dead+season+10+online+episodes PDF link annotation
    • https://eurosan.pl/user_images/file/nakofonamemir.pdfIn PDF document text
    • https://thehouseconcert.com/ckfinder/userfiles/files/jupakibilosapu.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/xebalasa.pdfIn PDF document text
    • http://www.rpv-drachten.nl/files/file/50713440432.pdfIn PDF document text
    • https://suprizpin.com/calisma2/files/uploads/zufimudepo.pdfIn PDF document text
    • http://tiramisu-o.com/yamituki-n/uploads/files/tejigugepaxogitotab.pdfIn PDF document text
    • https://kvzriu.org/images/file/gizot.pdfIn PDF document text
    • http://cwpni.com/userData/ebizro_board/file/65736838445.pdfIn PDF document text
    • http://shethof.ch/cgi-bin/dynamisch/file/nafadekoxu.pdfIn PDF document text
    • http://musicfriend.vn/public/default/ckeditor/files/dakep.pdfIn PDF document text
    • http://logtech.cz/foto/Image/file/vexejonifupewuxexab.pdfIn PDF document text
    • http://scsytech.com/upload/files/27618259790.pdfIn PDF document text
    • https://nacituran.com/userfiles/file/56160233728.pdfIn PDF document text
    • https://bbu.vn/Images_upload/files/simitafadavo.pdfIn PDF document text
    • http://wonderpanel.com/app/webroot/img/file/97460278590.pdfIn PDF document text
    • http://bebsulmare.com/userfiles/files/tasidagadiluz.pdfIn PDF document text
    • http://studiocalcinoni.com/userfiles/files/xufevituweripipum.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/161397ebdaba12---12574382702.pdfIn PDF document text
    • http://custom-mugs-factory.com/uploadfile/files/rerugufuvezodofonuzofod.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2aeab5ffc---6483760061.pdfIn PDF document text
    • http://ambulatorioveterinariomariani.it/userfiles/files/mexalatapevejafejiv.pdfIn PDF document text
    • http://wecans.net/_UploadFile/Images/file/poliwumefekugijaminomab.pdfIn PDF document text
    • http://thegioimaychaybo.com/app/webroot/uploads/files/86639520354.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16136bc329858a---lulejarepubomipuzegafes.pdfIn PDF document text
    • http://rotang.net/userfiles/file/97659201384.pdfIn PDF document text
    • 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_off0000dc7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC7B 10788 bytes
SHA-256: afd3c2d51c87b72f435b5fc8b928b2304368a2a0e42b9d8b4b22e62bc1ad67c5
font_01_sfnt_off0000f517.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF517 18716 bytes
SHA-256: a131e1742cb51067a5a19525f25ecd361cedf75b9321138f61f50fc94af991f1
font_02_sfnt_off00012617.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12617 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1