Malicious PDF — malware analysis report

Static analysis result for SHA-256 859d86ddc0620401…

MALICIOUS

PDF

93.9 KB Created: 2021-09-20 07:56:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 820117ce6a5431f9675a1a05343d0505 SHA-1: 53cf80049642a2c1890bb6beee4af15010dab4e3 SHA-256: 859d86ddc0620401531a28dfa2be53b178b4b351219b634255668e8bbdb92864
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Numerous external URLs are embedded within the PDF, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports the attack pattern of luring users to potentially compromised or malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://synerhu.ru/uplcv?utm_term=quick+short+market+apk PDF link annotation
    • https://svarovanijelinek.cz/ckfinder/userfiles/files/rezijigisofotew.pdfIn PDF document text
    • https://brs.jo/userfiles/files/wowuji.pdfIn PDF document text
    • http://kalkulacka-hypo.cz/userfiles/files/gapulosolugo.pdfIn PDF document text
    • http://mmprogetti.it/userfiles/files/40780214986.pdfIn PDF document text
    • https://theipbuzz.com/images/file/gelosojobojanaxirome.pdfIn PDF document text
    • http://veraschwemmle.de/fckdata/file/26972315179.pdfIn PDF document text
    • http://suliaok.com/v15/Upload/file/2021912720172480.pdfIn PDF document text
    • http://aorganboys.handyfriendship.com/upload/files/maridojamefebarile.pdfIn PDF document text
    • http://taigesw.com/upload/files/86976373285.pdfIn PDF document text
    • http://ericshartman.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xuroxonatunevuretexifov.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16143253965389---2325543801.pdfIn PDF document text
    • https://monyetmesum.com/contents/files/86014413318.pdfIn PDF document text
    • https://prosaison.fr/userfiles/files/dogevijenevumipavud.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/1f0ea66f1fcd6ee0d05c32b214b8c63b/55381856673.pdfIn PDF document text
    • http://atanasijornet.net/uploads/ckfinder/files/9708668929.pdfIn PDF document text
    • https://sma-dfgg.org/site/admin/file/22536179928.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/55506806396.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/vuxepo.pdfIn PDF document text
    • http://www.slenderclub.cz/ckfinder/userfiles/files/megufifexubirenegazuvokoj.pdfIn PDF document text
    • http://www.vandiestbrandstoffen.be/uploads/files/lulupovetixuwakarik.pdfIn PDF document text
    • https://samsunyapi.com/userfiles/files/bezomopisozonolo.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16147ed4f44f9f---wudabejajes.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_off00010524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10524 10740 bytes
SHA-256: 4b627f091a5787593978bf03a9e9bf1e66422f493c7de7dff9df016fec55987c
font_01_sfnt_off00011e00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E00 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013612.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13612 19800 bytes
SHA-256: a4e7aec4c293ba6f1479ea2958c9ae2c547bf71a472c64f4ba767cd423c9c596