Malicious PDF — malware analysis report

Static analysis result for SHA-256 870b850dd6557e54…

MALICIOUS

PDF

89.2 KB Created: 2021-06-22 12:41:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: aa203576bfef4cb7a993b5b9b9cbcd4b SHA-1: 35b6cfebf8f046513d78b2a81080b397f069f231 SHA-256: 870b850dd6557e54cc6dbcaa97dc062f945d7d8eec505907dbb2da5bca839b03
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://ketchas.ru/uplcv?utm_term=telugu+full+movie+watch+online PDF link annotation
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/cdd15e66df77729083488e575eb6ce8f/25892828698.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1608d608320250---52181875102.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee8fd4f91b---sasepora.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/9e1dad4e94e7f8bfaeabe752579a8213/sulabugedixakubifabexow.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/peviwulek.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/zirirukotikomop.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/1608a6573e7ab7---zogunuxoxumonozalot.pdfIn PDF document text
    • http://promador.pl/userfiles/file/87896735496.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16070cf6a715ff---firimanedinaxunukabu.pdfIn PDF document text
    • http://hoondb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079ba2b05362---livotakupepokepox.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086ad0b4cc60---dexuwepoxesibiruzopatokaj.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8fad2a554---nevavunidegiw.pdfIn PDF document text
    • https://n-zvuk.ru/upload/file/tusuguz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001062e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1062E 5004 bytes
SHA-256: 043c597af8497914df47eb030175a15f8679082981de46c8ee2d99f4a2b51bf8
font_01_sfnt_off00011720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11720 1896 bytes
SHA-256: 099d89093be102135c911a0e1d6cb497d4af1896e50bf9510546e5131dedf018
font_02_sfnt_off00012036.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12036 12412 bytes
SHA-256: 0e3679770947b1f9eb43df7afa412dc388654a621749afe7422e69ebff20d1e5
font_03_sfnt_off000149d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149D8 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333