Malicious PDF — malware analysis report

Static analysis result for SHA-256 d67cea5fa44233b5…

MALICIOUS

PDF

81.8 KB Created: 2021-08-04 07:07:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: 4b247dd216c6ccb39f218f6037b436af SHA-1: 0474d4a5ab329207c9eadd45017ddea072db852d SHA-256: d67cea5fa44233b50364b9ecda7d778d090c4d613bb6db8bf3883b7b0b54f32d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://synerhu.ru/uplcv?utm_term=ejercicios+de+suma+y+resta+de+fracciones+heterogeneas+para+imprimir PDF link annotation
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b11a5751077---bokegevedujob.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/1ebgpvbhkciig1staj6s04tb3k/vojemitiguxoze.pdfIn PDF document text
    • http://arcos-eff.it/userfiles/files/nafazuwemu.pdfIn PDF document text
    • http://wasserburg.pl/userfiles/file/45247203755.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0a35dee61---77438425057.pdfIn PDF document text
    • http://tahi.hu/ckfinder/userfiles/files/66617763922.pdfIn PDF document text
    • https://baoholaodong24.com/userfiles/file/8931723713.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/7c33c77ac61ff9c21e524ad2411c3980/83445214681.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/rasuzapanarizevu.pdfIn PDF document text
    • https://kiameds.com/images/upload/files/puwividag.pdfIn PDF document text
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609e40191a7d4---sebolomakonanazol.pdfIn PDF document text
    • https://wkd-uk.com/wp-content/plugins/super-forms/uploads/php/files/162c16ca3f16474559eae14539aa7571/nufofo.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/90d31800fcf08638c743d50454a8260f/nosazenivuxutes.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a04718303c5---78614981922.pdfIn PDF document text
    • http://chinajessie.com/seadata/data/uploads/img/file/162675263617.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607acd2106e14---33229239201.pdfIn PDF document text
    • https://colakcivi.com/userfiles/file/9333470004.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/62523bf6259413f05c098b98715f1f69/60295565384.pdfIn PDF document text
    • https://cihangirhotel.com/upload/ckfinder/files/80156794878.pdfIn PDF document text
    • https://benqmusicworkshop.com/fupload/file/besofejetimasiwakako.pdfIn PDF document text
    • http://hotelpenza58.ru/ckfinder/userfiles/files/28202185781.pdfIn PDF document text
    • https://butchercurnow.com/img/shop//contents/27347869935.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_off0000d82c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD82C 11348 bytes
SHA-256: 387544af9fac72a218fde540ffdaec49f5a1e249179d34d79fab4d7523f51c27
font_01_sfnt_off0000f280.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF280 17416 bytes
SHA-256: 287041ac888e2cb6b59e38bddc6d9f755a24ed5758a43c5f0ee5a4349ac60fee
font_02_sfnt_off00011edd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EDD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1