Malicious PDF — malware analysis report

Static analysis result for SHA-256 e838d6e3cafa9c5f…

MALICIOUS

PDF

80.7 KB Created: 2021-03-21 04:17:01 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 867e1cdd8048d8d9962eee2277821760 SHA-1: bf741b6051c454cc4cb843463dff83587ae61ac3 SHA-256: e838d6e3cafa9c5fdab256b41caa47a6ea4bd943f3bd8738cc507419b5b9c6e4
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the PDF structure itself is indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://golowaki.ru/award?keyword=inc+syllabus+for+bsc+nursing+1st+year+pdf+2020 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4367947/normal_6027f3c6e3ca8.pdfIn PDF document text
    • https://cdn.sqhk.co/widafopaj/wghShfg/41825494281.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4404745/normal_5fc8fdae52a51.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478408/normal_6052ddd49207e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380086/normal_6022fa2df1ac9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415331/normal_603ad10b508f1.pdfIn PDF document text
    • http://ejinaya.com/xelabik61y9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421039/normal_601e213d1fce3.pdfIn PDF document text
    • http://brumbum2.xyz/wevagaketonozonidasiwb4i1e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4406809/normal_6001f4378372d.pdfIn PDF document text
    • http://onsideball.info/kenmore_dehumidifier_filter_light_blinkingpcs7o.pdfIn PDF document text
    • http://uniques.space/523324996868dsal.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446496/normal_5ff9d03cb497d.pdfIn PDF document text
    • https://cdn.sqhk.co/gosukutusu/jhgjgij/58929299363.pdfIn PDF document text
    • https://cdn.sqhk.co/jujejorule/Ihcjahb/international_business_management_program_in_canada.pdfIn PDF document text
    • https://cdn.sqhk.co/rufomezin/hgtzlic/zovebijevosuxuj.pdfIn PDF document text
    • http://shop-kid-toys.online/word_2016_shortcutsi1mki.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://d102a0f2-001f-4998-bb0a-88ac30ac05b5.filesusr.com/ugd/771ea4_88155a73bddd4413b961a052388f81c6.pdf?index=trueIn PDF document text
    • http://sejofedavija.epizy.com/focus_group_discussion_guidelines.pdfIn PDF document text
    • https://4a0f17ac-6ce6-4c05-9546-25c48d39d9f7.filesusr.com/ugd/cd79e3_68dd61850dc242b7943bd642788296fc.pdf?index=trueIn PDF document text
    • http://lawazujazigefon.epizy.com/baxosemavetexewumodotozi.pdfIn PDF document text
    • https://8b83d164-5e56-46cc-b941-48f48810ddf3.filesusr.com/ugd/76ce43_befaabccdc464e5685894eec75f61148.pdf?index=trueIn PDF document text
    • https://53ebb62d-ddaf-432f-8dc3-1f4746653467.filesusr.com/ugd/bbd3cf_30bb5b44ccd0483eaf9c8525a53da527.pdf?index=trueIn 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_off0000f964.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF964 5828 bytes
SHA-256: 03dd44d7412907e484a7e0c2d9c4151365f2a7a5a948a61a96b8673ea36df9d1
font_01_sfnt_off00010d52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D52 11064 bytes
SHA-256: ef9cfad8eb3083cae8151bd076c1ddaec8f662cbcb8155035be938f453a30005