Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac540eeb9cb0698f…

MALICIOUS

PDF

72.2 KB Created: 2021-06-24 01:47:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 7178e9f5f4d67dd3e5b7d956bbf9af0a SHA-1: 46b795ba70dba13593f3ba18bc26a8f21480623c SHA-256: ac540eeb9cb0698f06be209b5578f30501b08910d6ec698c00c3c4dc27232098
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links pointing to compromised WordPress sites, likely intended to host and distribute further malicious content. The ML classifier strongly indicates maliciousness, and the link farm structure suggests an attempt to lure users to download or execute additional payloads. No scripts were extracted, limiting the analysis of direct execution methods.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a0e75b366---84762754620.pdf In PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/pgk318320pdshopmn75tpnq2u3/32863203815.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16080774e1ae04---sadomu.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a809af0bb---sedodofajodoturanomaz.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/44b318986e44740ec1955c0ebc65a1c7/34894514167.pdfIn PDF document text
    • http://mkngsp.ru/upload/files/megijasoxujifime.pdfIn PDF document text
    • https://pousadamarazul.tur.br/wp-content/plugins/formcraft/file-upload/server/content/files/160823869ab979---25862708324.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/339bfc8a104d1982cfe68bfe0b579a8c/fixodudapugeja.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/gvmoda8nhrh9kc5m3v78f328no/tonadofatijumusamarixu.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16099be7c96d84---nakanozumakitobuwaxo.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8e1385107---welox.pdfIn PDF document text
    • http://yuhenganquan.com/userfiles/file/20210527041746_1300818705.pdfIn PDF document text
    • http://hungbuloon.com/media/ftp/file/89051503813.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/1432de50885773750af5bb6cd2bf41c3/fitejadokire.pdfIn PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/sooul1qrmri5ms7v9rgim8l7hj/nakivufazutetix.pdfIn PDF document text
    • http://vanharteyoga.nl/uploads/files/8671550752.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=class+7+cbse+maths+worksheetsPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dbc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC3 5320 bytes
SHA-256: 945a4d4e3327e3b7100a4b6ba4d3c6fbc050d0330a3efbcc78a53d74e10e1159
font_01_sfnt_off0000edc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDC4 11232 bytes
SHA-256: 14b5ce4b862b0ecf391fcba5287c2a5ffd8d29bd30e3f096f8987da6009fbbc2