Malicious PDF — malware analysis report

Static analysis result for SHA-256 5861109c420cb895…

MALICIOUS

PDF

78.9 KB Created: 2021-09-19 14:59:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 37d5921125cbec34c5c0f17677ea4029 SHA-1: 19e8e2b28c7fb02ac50fe3a951cf6f9bab8b5b61 SHA-256: 5861109c420cb8958379913b7874efdfe4d5de4ac6e8cba365f2c3e79c50f3cf
156 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm. Several extracted URLs point to compromised CMS upload directories or disposable hosting, suggesting an attempt to lure users to malicious content. The document body is unreadable binary data, providing no direct content clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 http://elosc.com/upFile/file///ITX202109180312486753.pdf In PDF document text
    • https://testagenda1.myagenda.cz/pictures/editor/files/lokifixu.pdfIn PDF document text
    • http://bernendorf.ru/userfiles/file/fudetizolodefewikamulado.pdfIn PDF document text
    • https://cuichi177.com/uploads/files/202109072004065516.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/waxafigakiralobema.pdfIn PDF document text
    • http://titusauto.hu/kepek/file/63278155423.pdfIn PDF document text
    • http://celyroknaterase.sk/editor_uploads/system/files/30872817412.pdfIn PDF document text
    • http://onfireinteriors.com/userfiles/xulatasuwobobogafifejotis.pdfIn PDF document text
    • http://designklasse.de/ckfinder/userfiles/files/36985519013.pdfIn PDF document text
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/segamapunexas.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/lcef8n3hd7hg4tc3rjo4abp4du/46655345044.pdfIn PDF document text
    • https://stalbeckers.nl/userfiles/image/file/zufufotakorinekuxaliv.pdfIn PDF document text
    • https://3rproject.eu/ckfinder/userfiles/files/rubil.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/lno2u53vedr8v8sis3jqmoh0d1/busazivapiluwivenor.pdfIn PDF document text
    • https://thuaphatlaihoanghuy.com/uploads/files/1587626246.pdfIn PDF document text
    • https://bomberosdenavarra.com/userfiles_nexo/files/12345764974.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/27035665915.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/nde83iuhl2meunbvk861fl6f1s/88020914707.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/61514613078.pdfIn PDF document text
    • https://onthespothousing.com/userfiles/file/25932640881.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/161468e8da9245---potogebuzewomatifonegosuv.pdfIn PDF document text
    • http://clubesquilacoma.com/uploads/files/67773330357.pdfIn PDF document text
    • https://gretajensen.com/ckfinder/userfiles/files/zufotat.pdfIn PDF document text
    • http://baikalspring.ru/ckfinder/userfiles/files/95567224943.pdfIn PDF document text
    • https://haidangpc.com/contents/files/25806957572.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=pubg+mobile+lite+apk+2019PDF 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_off0000ca27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA27 11016 bytes
SHA-256: 0b1e54fb6bb7269acb02126f93f187133d5d675c6fff7904de88c6aaccadcd40
font_01_sfnt_off0000e3a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3A0 19432 bytes
SHA-256: e2cc9a6a49d8b9455a24ea17abe9c63464bda427f44e20f965252ca2aae2ae83
font_02_sfnt_off000116a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1