Malicious PDF — malware analysis report

Static analysis result for SHA-256 c41de216c70fa78a…

MALICIOUS

PDF

81.1 KB Created: 2021-09-18 04:01:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d9702a7edeb0e8f53c5167b99f42ff38 SHA-1: 5bb8f87f5930a75675b773adc1a2879a928ac233 SHA-256: c41de216c70fa78a76174dc4c99cc4c4e0bf7218aaaab847b501d7c4fe79b517
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by an ML classifier as malicious. It contains a large number of embedded URLs pointing to various domains, suggesting a link farm or phishing attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically indicates a non-clustered link farm on disposable hosting, reinforcing the malicious intent. No scripts were extracted, but the sheer volume of external links points towards an attempt to redirect the user to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 4

  • 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://laborke.ru/uplcv?utm_term=search+volume+data PDF link annotation
    • https://landtop.com/filespath/files/20210916080926.pdfIn PDF document text
    • http://sysquare.com/UserFiles/files/24658942899.pdfIn PDF document text
    • http://trufeel.com/ckeditor/ckfinder/uploadfile/files/91152739494.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/zuzutividofiboraxotuw.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142dfba8597f---99937233855.pdfIn PDF document text
    • http://grandwatergatehotel.com/upfile_hotel/files/zoxugesemu.pdfIn PDF document text
    • https://dispecom.com/cms_dispecom/sgi_userfiles/userfiles/files/4686303018.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/17120449083.pdfIn PDF document text
    • https://madspot.dk/ckfinder/userfiles/files/gojovakalewisuwaxabex.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/161317667302c1---86299492323.pdfIn PDF document text
    • http://encino.ilovepokebar.com/uploads/files/18889940099.pdfIn PDF document text
    • http://nesemlak.com/test/images/uploads/files/82478709245.pdfIn PDF document text
    • http://kovospm.cz/fotky/file/9032705973.pdfIn PDF document text
    • https://bodegoncriollo.com/userfiles/file/35248724598.pdfIn PDF document text
    • http://floramarble.com/uploads/32251576635.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/wanikoxovake.pdfIn PDF document text
    • http://zhouzhuank.com/v15/Upload/file/2021911750464178.pdfIn PDF document text
    • http://mashhadgardi724.ir/basefile/mashhadgardi724/files/58493568131.pdfIn PDF document text
    • http://rucodelniza.ru/userfiles/file/44898336451.pdfIn PDF document text
    • https://mk-sito.it/uploads/file/64823382349.pdfIn PDF document text
    • http://ke-sen.com/userfiles/file/1631401534.pdfIn PDF document text
    • https://luatkhangthai.vn/upload/fck/file/zuzimu.pdfIn PDF document text
    • https://repairbase.net/FCKeditor/editor/filemanager/connectors/php/images/file/misojimo.pdfIn PDF document text
    • https://jairdefreitas.com/ckfinder/userfiles/files/teborumoxi.pdfIn PDF document text
    • http://www.optimizecost.com/admin/ficheros_fckedit_subidos/64275033941.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_off0000da49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f260.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF260 10512 bytes
SHA-256: cb5f484fc84e794af630edf73a69e65003746a60de70847ba1248eae85f86aed
font_02_sfnt_off00010a5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A5A 17256 bytes
SHA-256: 083c4e728880c90b9d71a2a667f8ccbb743f0c159295db27ea218a4084b5d9ae