Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8357928352ab859…

MALICIOUS

PDF

80.3 KB Created: 2021-09-03 23:10:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 84cd361003d8f373909f654639de9230 SHA-1: 193908f525ef72f17d523dda2d0b7b8da8146097 SHA-256: c8357928352ab859e9100e997b78c58317813ba15d58a6318620bc57d9615b19
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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/1a21e90e8b387c8a5f60d8050f693119/12907188275.pdf In PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/15f61437c20ac5489e422e709587161c/runekerowowiniwisir.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16070f0c8755fd---lobodetemikulusofurom.pdfIn PDF document text
    • http://www.knickmeier.net/images/pageimg/file/44306094953.pdfIn PDF document text
    • http://rsport.eu/yonexshop/static/file/94591073131.pdfIn PDF document text
    • http://abbwingslynnhaven.com/uploads/files/23263766089.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/160df5f51049cf---85329789840.pdfIn PDF document text
    • http://whatdwellswithin.com/file/muxunexamakemozifod.pdfIn PDF document text
    • http://xn----8sbemnkjd7bfu.xn--p1ai/design/img/upload/file/78776559085.pdfIn PDF document text
    • http://eventologia.com/userfiles/files/68604949367.pdfIn PDF document text
    • http://ashioke.com/images/library/File/kisixuzu.pdfIn PDF document text
    • https://peilimineko.com/userfiles/file/2821944995.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/ginikusevav.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094238fb7561---sigininelubijidimolofo.pdfIn PDF document text
    • http://naoshima-habitant.com/naniwemenebol.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/25744ee8f16e8fcbda61e87f943de96c/74779817462.pdfIn PDF document text
    • https://monuments-msk.ru/wp-content/plugins/super-forms/uploads/php/files/38d83ebc1f4fe96bb5d295db0f194b5f/bafefedevizavizumuxex.pdfIn PDF document text
    • https://tahubunting1.com/contents//files/xevaxologedalapukole.pdfIn PDF document text
    • http://cu-mbc.com/ckfinder/userfiles/files/95372919417.pdfIn PDF document text
    • https://ijacr.net/assets_admin/ckfinder/core/connector/php/uploads/files/25855211593.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/zowuso.pdfIn PDF document text
    • https://kitapkapla.com/upload/ckfinder/files/63389582609.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=cvor+practice+test+pdfPDF 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_off0000d90a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD90A 16492 bytes
SHA-256: 1007ac9c606ab51eddde544bd896d06034712d985a5632ffa6184e3d0dba3edf
font_01_sfnt_off0001034f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1034F 10560 bytes
SHA-256: 989776b175e7cd16e4f28a08424e6881d6fb777a0d01ff6ca5dec633382b4202
font_02_sfnt_off00011b98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1