Malicious PDF — malware analysis report

Static analysis result for SHA-256 31ad34c8ed8a7a46…

MALICIOUS

PDF

80.8 KB Created: 2021-06-23 03:07:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 3f7e15ebb08954b9011b03001e115ee1 SHA-1: a547cdea1f4116bb4e2087a4977290a65e58a282 SHA-256: 31ad34c8ed8a7a46f1eedd4c20df1e3e42ba7790075c5175c37463d6315dbc7a
104 Risk Score

Malware Insights

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

The PDF document exhibits characteristics of a malicious link farm, with numerous URLs pointing to compromised WordPress sites and disposable hosting. The ML classifier strongly flagged this PDF as malicious, and heuristics indicate it contains external URIs and a call-to-action button, suggesting a lure for users to download further malicious content. The document body itself is heavily obfuscated and contains metadata related to its creation, but does not provide clear instructions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/a5g89b7u39547qoj2abn6s8tqs/zinitin.pdf In PDF document text
    • http://botosani.ro/img/uploads/file/tirawuxija.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/0ff8e09ujh1493s0ancccves0g/denewodibenajetenonolog.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/2d1fc635bbb4adbd9ede46b2401b70da/56661087578.pdfIn PDF document text
    • http://gloria-eurex.com/20164790143.pdfIn PDF document text
    • http://dtcguild.org/clients/80367/File/43840561115.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16081be5070212---77735151883.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/e476ejah9onov8p8097p9v701s/45786776099.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/5e66dd7e0c9ef8c672647b921bdcbbff/bozovufonevifel.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/4rflbfnk9mf5fgp1h78ii2hk6j/pukaf.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/jetavasidik.pdfIn PDF document text
    • http://www.bash.cl/media/file/29771798483.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/e40abe96e836eca7d8c7320c35697501/44539153748.pdfIn PDF document text
    • http://endustriyelkiralama.com/wp-content/plugins/super-forms/uploads/php/files/gd5qfqtasheq5be8o8299ur8qv/82447043387.pdfIn PDF document text
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a1bd9316ae9---16111004380.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16080211cd897e---bigure.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/GLLx1DTH0VQ/uplcv?utm_term=dav+english+literature+class+8+solutions+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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fcdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCDF 5672 bytes
SHA-256: 58e3c46038ec2bbe3002826486bc400491a8de9188ee0d0dd760e3936b2199b0
font_01_sfnt_off0001103b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1103B 11104 bytes
SHA-256: 576b5c4f63c528ec836888eec28159e5f4284a958ee0cf26aea3c266eb0306d5