Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b7ef926de0c2713…

MALICIOUS

PDF

70.7 KB Created: 2021-05-10 03:51:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 097f906a6d806c811f2971d6180542e3 SHA-1: 56ea98a53726d963eb482a47e6b5421df32b2d1d SHA-256: 8b7ef926de0c2713405a8898568336c2b3f96985a484fe462099a76455c5b4b7
96 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, identified as a link farm. The ML classifier strongly flagged this PDF as malicious, and heuristics indicate it leverages compromised CMS upload storage. The primary purpose appears to be directing users to potentially malicious content hosted on these compromised sites.

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 https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/c65331236b8f09e3fc500de818c7f005/kurejixopuwabatevi.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093f74932f15---9614977718.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160983eaa07310---vipetovugesanabifi.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16096a46ca5a99---14436074063.pdfIn PDF document text
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/33ef4a9bd14970483118bfa209aa2cb3/wizan.pdfIn PDF document text
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/37b1202c559414ba777913ee829482f5/37392198421.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/f6d2286873f81f93c565e4e99a54bbac/37762104832.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dff529397d---85205330219.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/08ee2eb53ad9df5174990b02e29e679e/92310143790.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160726287c583b---boritudoxexefugafiwo.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e561ee3266---ruvadago.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e16d4b5e23---jijisanisepep.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/ia838d9r033d6m8bmv3k8p8069/51407853255.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608858669c4cd---3040238434.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/9ba62d8c0387df3effc2ce648451687f/bujopaforirobewijoxoxoku.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/~3/1xuhb7AK25c/uplcv?utm_term=aprende+a+leer+con+pipo+pdfPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cbd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBD4 4960 bytes
SHA-256: a2a646baf8559a2a563e8bdc07d9009ec26a7501cee6932e6466d9f6c406354d
font_01_sfnt_off0000dcc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC0 2040 bytes
SHA-256: a333c8904888d65748eb12410cab2a0948450dba11de826f531480ce6969f020
font_02_sfnt_off0000e644.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE644 11732 bytes
SHA-256: c7dbe08611f0fce264cf8ef0f7ea04c2c9020015e7b114943a32f54397828b46