Malicious PDF — malware analysis report

Static analysis result for SHA-256 5373108f9a1957de…

MALICIOUS

PDF

69.4 KB Created: 2021-05-27 14:05:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: ec3e19a3dac5838bd4c4733371189259 SHA-1: bf3783f49f6235f5466730cba5db991c1e8993a4 SHA-256: 5373108f9a1957de391b53b6c9faffb006af5687b319bbc390acd05ed7c093f7
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, suggesting an attempt to distribute malicious files. The ML classifier strongly indicated maliciousness, and the heuristic firings related to link farms and external URIs support this assessment. No scripts were extracted, but the presence of numerous links to potentially compromised domains is a strong indicator of malicious intent.

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.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607aafe39bebf---61794066982.pdf In PDF document text
    • http://axwelindia.com/uploads/ketitefabi.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/aa5b71ae8ccc7aa9b73f5f58b4d72e4d/tufematelujureb.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9c52d588a0---28973382939.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/d0a7fd3d8f08cb19dcc263d6e23b9c5a/gibuviwepalesasuboja.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/2a5d9f63518cdc85ee7fe63141046dde/ropejagomareropiz.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/8700c801f03f8cc52a280e9d0f297518/11599353966.pdfIn PDF document text
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16073bb557bd7a---23929786756.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fcb3890a2b---51961485120.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/305ee4f869d42f7f5dbd62337ebbad6e/57269127472.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2f7dabb90---62016241565.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/1465982b01306cc96112b70bd2191f7f/73391716438.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/a04c8krbtfgu3uvp1rgmo4jgpf/gopugelusijipanofivuxa.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/kunamawetoguraxufenipupo.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/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=general+mobile+pc+suite+indir+t%25C3%25BCrk%25C3%25A7ePDF 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_off0000cefb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEFB 5756 bytes
SHA-256: 919f3da818e2eeedf4cce6cf6469f45d9c12ff5b5d73bde7150259f677e0480c
font_01_sfnt_off0000e1f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1F3 11468 bytes
SHA-256: d00ec117f8711ad0cbe65c95f367d30f7fba8cc416624cfe17010fce01c29b84