Malicious PDF — malware analysis report

Static analysis result for SHA-256 1839c13eaf1c998e…

MALICIOUS

PDF

48.9 KB Created: 2020-10-17 01:17:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 40d78585cf12b33ec0b6c721fb491d16 SHA-1: 7c0c9699957b91d7b39bc97d98faeb213d5db8ba SHA-256: 1839c13eaf1c998e5c3b55c91bfb26d8c7ebeef38b46958195eae41d086bb805
184 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with one pointing to a known malicious redirector. The document body, though heavily obfuscated, contains the URL 'https://cctraff.ru/strik?keyword=interactive+porn+stories', which is flagged as malicious. The presence of numerous links to external PDFs, including one on disposable hosting, suggests a link farm or redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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.
  • 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://cctraff.ru/strik?keyword=interactive+porn+stories In PDF document text
    • https://cdn-cms.f-static.net/uploads/4369322/normal_5f88b4ee83746.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366369/normal_5f87176a19c5f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365582/normal_5f870cb57c3ac.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367646/normal_5f88023240bce.pdfIn PDF document text
    • https://gimejexoxixaza.weebly.com/uploads/1/3/1/8/131872185/kadupe_ripovu_jozovagazemewe.pdfIn PDF document text
    • https://viweposedijul.weebly.com/uploads/1/3/1/0/131070314/1371be6145321.pdfIn PDF document text
    • https://jelamiwigu.weebly.com/uploads/1/3/1/3/131382248/pufumolumodo.pdfIn PDF document text
    • https://xojerajap.weebly.com/uploads/1/3/1/3/131384359/2122744.pdfIn PDF document text
    • https://rudofodirofebas.weebly.com/uploads/1/3/0/7/130739781/3228609.pdfIn PDF document text
    • https://fuparududewon.weebly.com/uploads/1/3/1/8/131856041/9897457.pdfIn PDF document text
    • https://xawuwotogot.weebly.com/uploads/1/3/2/6/132695388/2395d167f0c77.pdfIn PDF document text
    • https://guwomenod.weebly.com/uploads/1/3/0/8/130873843/3409757.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/2625d7fb-83e2-49bf-affb-e328176a3f54/jetepe.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/888556e5-c7b0-41a7-8008-590471a106fd/kujur.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8d08c54f-5370-4493-8407-ae399311479f/solokizomawibodesedizi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a866ef1-19fb-492f-a2a3-52a49b2511c1/lesos.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2a862c68-0d90-4e95-8acc-0b92cfb646a2/99814396449.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/210ecd32-2ebc-4aed-b9fa-6d1502a6db67/tibivexidegufuwatefax.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9de4b846-a2ae-4d66-8cbc-91b7003f3882/3430184143.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0506/0214/8005/files/vusod.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/0419/9075/files/albert_l._lord.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0497/6050/1921/files/teks_pembukaan_uud_1945_untuk_upacara.pdfIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00008065.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8065 4892 bytes
SHA-256: 7ecd832c1d7b35e5bf0874ec8105894b44fe6dc5a9b7d4c5625b82d42e86ccf7
font_01_sfnt_off00009111.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9111 11156 bytes
SHA-256: 314151a7063ce31e1595f9f6117c5f335fb3295cb56a58ec82a125536a71ac9e