Malicious PDF — malware analysis report

Static analysis result for SHA-256 666f5c258462279e…

MALICIOUS

PDF

70.9 KB Created: 2021-06-21 19:27:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 867b6e548761f9653f766db26cddeee8 SHA-1: 19c045431e240837ee7bc4f9b49d2d5a6b9a6d13 SHA-256: 666f5c258462279e5757edd115981982c5fa09bce9dba6671431a3d041ab1cf8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs that point to compromised CMS upload storage and disposable hosting, suggesting it functions as a link farm to distribute further malicious content. The presence of PDF_URI and EMBEDDED_URL heuristics further supports this, indicating the document's primary purpose is to redirect users to external, potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=polarization+by+double+refraction+pdf PDF link annotation
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160775186e2ea6---zitawamuwerejamunolita.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160991ed23e7ee---bomizimiduzakakafejugaf.pdfIn PDF document text
    • https://gwynharmon.com/home/gwyn/public_html/ckfinder/userfiles/files/99322183743.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b8d75cc9b5---rulanesesepakose.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/36783738860.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607e5dfd1579b---37246834401.pdfIn PDF document text
    • http://loscogliodifavignana.it/userfiles/files/pumerubapuninowelumapuf.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16087dd8d5a418---dubekomukipirop.pdfIn PDF document text
    • http://goref.ru/files/file/musogewaseziv.pdfIn PDF document text
    • http://ksnjl.com/userfiles/files/xizubugigupokinot.pdfIn PDF document text
    • http://www.heksan.com.pl/file/nejekerepilojuwuxuve.pdfIn PDF document text
    • http://envigest.cz/upload/file/sojakoz.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160982de323ffc---midipipafox.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160988b33a5bcc---7250236353.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607c88dfdd03f---42680312065.pdfIn PDF document text
    • http://teraval.cz/res/file/widunatiwonajapufi.pdfIn PDF document text
    • http://apcmagon.com/userfiles/61493959286.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6BC 5264 bytes
SHA-256: 150f4bf9b6354d76a04c64bdc7c64dbad4bc6285401cbbc52eaf421eb5be2e1a
font_01_sfnt_off0000e8c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8C3 11076 bytes
SHA-256: dc4a1a47891779988d7b8e456c6e02cb3e5f92159ade889bf4f4b302c09e495a