Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdd6821262d72834…

MALICIOUS

PDF

109.6 KB Created: 2021-10-05 09:12:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 121be17a2d02ddf7b9e7025e764eced7 SHA-1: c887ada70ad97bfd4891d9ddc9adcb5d77dab203 SHA-256: cdd6821262d72834fe236503e47633d5d9877c6917fca71e13ca4faec6663d3c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as a link farm pointing to compromised WordPress uploads and disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly support its malicious nature. The embedded URLs are the primary indicators of compromise, likely leading to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://wastran.ru/uplcv?utm_term=the+ant+and+the+grasshopper PDF link annotation
    • http://thanhtindesign.vn/uploads/image/files/92145334981.pdfIn PDF document text
    • http://funkyspa.net/ckfinder/userfiles/files/34192667351.pdfIn PDF document text
    • http://unitez.net/images/newtech/files/79101740436.pdfIn PDF document text
    • http://twtqedu.com/userData/ebizro_board/file/musonijul.pdfIn PDF document text
    • http://mis.nrru.ac.th/gradjournal/ckfinder/userfiles/files/gazakaxefumulunisariwam.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/7917c65c2b5473c16e09396f7c35f413/75472539467.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/rosevasamivigikovude.pdfIn PDF document text
    • http://adimhukuk.com/resimler/files/radofiradenawemi.pdfIn PDF document text
    • http://1night2daytour.com/ckupload/files/tadovupitaliluvaf.pdfIn PDF document text
    • https://artbynela.com/uploads/file/50948117071.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614440fc3024a---zizijovelujugubupedit.pdfIn PDF document text
    • http://wasserentkalkung.at/ckfinder/userfiles/files/kagapexuki.pdfIn PDF document text
    • https://tjp2-hotlink-j3t.com/contents/files/1881896632.pdfIn PDF document text
    • http://polskienarty.pl/data/aktualnosci_imgs/file/65710425325.pdfIn PDF document text
    • http://inistor.com/ufiles/files/mebajimilewujesuto.pdfIn PDF document text
    • http://geometrarontani.it/userfiles/files/98814149021.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/161302126ad98b---bapevajadekanoku.pdfIn PDF document text
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/72127437490.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/zagexumegubebere.pdfIn PDF document text
    • http://chukguwang.com/files/fckeditor/file/88516603385.pdfIn PDF document text
    • http://masan315.net/board/imagefile/file/91343825341.pdfIn PDF document text
    • https://binarbaidrealestate.com/public_html/userfiles/file/mumoruposiwavujiliv.pdfIn PDF document text
    • http://vkts.se/userfiles/file/pomurafiluv.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/16158f55c668ee---vunuwumexeje.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_off000140a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140A4 10496 bytes
SHA-256: e48262580faa07f920b49e846de15fca850dbc144d89f42584cc3ab81b9a05c5
font_01_sfnt_off00015839.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15839 21908 bytes
SHA-256: 337f07736d1e3818ff84553819ebc65f07f49532a325f8f69087b6df84f7f22b
font_02_sfnt_off0001906f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1906F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1