Malicious PDF — malware analysis report

Static analysis result for SHA-256 8043dbd17534bf7f…

MALICIOUS

PDF

88.1 KB Created: 2021-06-29 17:13:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: fe874d08fc02d4982def91c274903726 SHA-1: c835b6141b132e5db078c0e2b65324c8dc266aae SHA-256: 8043dbd17534bf7f83209a7c19d5a82ca87324a25b84c884f9ce53ac7336c783
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. While no scripts were explicitly extracted, the PDF structure and URL patterns suggest it is designed to lead users to phishing or malware download pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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 http://ozdoby-betonowe21.pl/Upload/file/jagomidejatiloxuvu.pdf In PDF document text
    • http://erex.hu/upload/file/97578479898.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0658cd311---zewilobexetedafeviridaved.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/da2183e8f9b555ee76537e34e3c1ae01/14901059310.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160813b0998227---8211093757.pdfIn PDF document text
    • https://xn--z4qq44i.tw/upload/actfiles/nevupisuz.pdfIn PDF document text
    • https://cplastik.com/data/cms/file/51140785662.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa837a963a4---jalalivijixuwavugugev.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/xosiwutetajerax.pdfIn PDF document text
    • https://fundreamz.com/ckfinder/userfiles/files/davekorapojidepa.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb779e74e05---44345732891.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16084d42faad9b---datesotiwutiwukubilewop.pdfIn PDF document text
    • http://lapenya.cat/imgjovesnaves/file/40009280290.pdfIn PDF document text
    • http://appletechsolutions.com/userfiles/file/36544013759.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/c2f88ee83fe29b7737aa6be7ba76ae24/zugivipubavazareselo.pdfIn PDF document text
    • http://barcelonahotel.vn/UpLoadFile/file/68620609925.pdfIn PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/8oqg8aoisdbt9hnjbn23o6oq67/xasirovifi.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/3b07f4def7a3133cef25cfc05b89322c/3002944468.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a0e60f8774a---nudetiterenajuwoxatuwe.pdfIn PDF document text
    • https://twr1115.net/files/fckeditor/file/9587997814.pdfIn PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/wosaj.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/8ltfs9r6na76vbud74u6hvo9nm/nonuboluzavapugakoxujax.pdfIn PDF document text
    • https://smilepaper.tw/archive/upload/files/59642749611.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=giant%27s+causeway+visitor+centrePDF 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_off0000f226.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF226 18492 bytes
SHA-256: 0c81e35452b23604e186b596974141f9c2d4d2ff495f21670d9cd890001942ab
font_01_sfnt_off0001223c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1223C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013a53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A53 10616 bytes
SHA-256: 66bed47cae2cc1db98e065cea4d43dd8cc7e809b687946f98b16b42f42ce1f8d