Malicious PDF — malware analysis report

Static analysis result for SHA-256 92a3fd4710e8c504…

MALICIOUS

PDF

80.3 KB Created: 2021-09-04 00:30:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: aa8c5f68959faa2425865ceeab2e92f7 SHA-1: 226afce7f254e2db2732cad24f77ddff42fdf480 SHA-256: 92a3fd4710e8c504c60fe379eb7283c1ae47bb196f3ab94663ee1caf03e65ed4
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a link farm designed to distribute malicious content or manipulate search engine results. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the PDF structure and URL patterns suggest an attempt to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160862e6867648---18033986030.pdf In PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/07f1530f2267af4bb5137a60a3f82094/kivodago.pdfIn PDF document text
    • http://mtlebanon62.com/clients/5/5e/5ee551a8be14a26d7d76bc5e90dd1372/File/febidegonuru.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/14839911863.pdfIn PDF document text
    • https://webhosting4.net/media/file/guwizijekamaxojame.pdfIn PDF document text
    • http://w-f-l.de/user_img/file/bumumewomilorivon.pdfIn PDF document text
    • https://manusingh.org/scgtest/eec-new/codelibrary/ckeditor/ckfinder/userfiles/files/630966072.pdfIn PDF document text
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/94990615517.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16081efc46986f---rejipemapovaded.pdfIn PDF document text
    • https://oferta.lt/i/File/ludoxupafofo.pdfIn PDF document text
    • http://needychild.org/ckfinder/userfiles/files/32183517102.pdfIn PDF document text
    • https://diaochue.vn/userfiles/file/73711074904.pdfIn PDF document text
    • http://amesonsofallen.org/clients/53156/File/mulareleduluxatup.pdfIn PDF document text
    • http://jiangsutravel.kr/userfiles/files/20210623_111441.pdfIn PDF document text
    • https://uslugiinzynierskie.com/eurostyl/photos/file/61070373454.pdfIn PDF document text
    • https://grafconsulting.pl/Upload/file/26453379973.pdfIn PDF document text
    • http://tksvolga.ru/userfiles/file/6049542661.pdfIn PDF document text
    • http://koreadramatour.com/FileData/ckfinder/files/20210628_F4913C93353AFE27.pdfIn PDF document text
    • https://maharajganjtimes.com/assets/ckfinder/core/connector/php/uploads/files/mimesasezega.pdfIn PDF document text
    • http://uci.ir/userfiles/file/nelupipade.pdfIn PDF document text
    • https://alsultantrading.ae/userfiles/files/63616508850.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/kuzoverozabujorikijifef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=was+were+worksheet+class+2PDF 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_off0000d759.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD759 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF70 10420 bytes
SHA-256: ccfb6ea54584dd1e9d69f0b97b2319700b5b097577c8b5993730c1960459e889
font_02_sfnt_off0001075c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1075C 17080 bytes
SHA-256: fd6c307aa445d93e8ebd867b2f132d85894ecb19757c95df465b0e33406bfce3