Malicious PDF — malware analysis report

Static analysis result for SHA-256 90844c84a71230d9…

MALICIOUS

PDF

69.8 KB Created: 2021-09-22 17:08:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e8e98f023045b59317c552339dfd1d11 SHA-1: 4d362c34060090533d8f5a48766fcbaf45319d06 SHA-256: 90844c84a71230d90008c74712b373f681227031257b747199b3cf79eb7a6a51
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, characteristic of a link farm designed to obscure the ultimate destination. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic confirms this behavior, indicating a high likelihood of phishing or malware distribution. Although no scripts were explicitly extracted, the ML classifier and ClamAV detection strongly suggest malicious intent, likely involving the exploitation of PDF vulnerabilities or redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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 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://med-os.com/user_upload/file/62224415257.pdf In PDF document text
    • http://gesundheit-im-blog.de/userfiles/file/35315819121.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/bujuso.pdfIn PDF document text
    • http://imosa.asia/uploads/files/202109040512207185.pdfIn PDF document text
    • http://sghr.ca/upload/ckfinder/files/nusitizakufijiriti.pdfIn PDF document text
    • https://rougezenekar.hu/files/file/27710486754.pdfIn PDF document text
    • https://questyme.ca/userfiles/file/noxozefizef.pdfIn PDF document text
    • http://kammerchor-lindau.com/file/pipusepujademezubifasus.pdfIn PDF document text
    • https://watfordfairtrade.org/app/webroot/img/files/50188417706.pdfIn PDF document text
    • https://indobaliart.com/sitefiles/file/15829546839.pdfIn PDF document text
    • http://kuryakyn.ru/userfiles/file/84890248867.pdfIn PDF document text
    • http://phutungotodungha.com/img/files/mekuroji.pdfIn PDF document text
    • http://eszixv.hu/ckfinder/userfiles/files/60271227707.pdfIn PDF document text
    • https://nomortiga.com/contents/files/13886367449.pdfIn PDF document text
    • http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210909_024715.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/xozoxurujiw.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/16146d11eb99bc---28354475542.pdfIn PDF document text
    • https://optimumquestsolutions.com/ckfinder/userfiles/files/xuzexozavonabuvumalupoki.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/upbt3lda16bj21n614e3c96p61/lonilegekejesujujojato.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/91911032101.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/32176494696.pdfIn PDF document text
    • https://argekaucuk.com/nbg/upload/files/babab.pdfIn PDF document text
    • http://www.specemc.ru/upload/files/31291936498.pdfIn PDF document text
    • https://am-system.eu/ckfinder/userfiles/files/gavokofuzu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=funny+w+words+to+describe+someonePDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b25c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB25C 15192 bytes
SHA-256: fbb0cce25485eed7eb4d25e69b8cebc46e914804c158c0b24f591e4f4d766744
font_01_sfnt_off0000d8ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8AE 10740 bytes
SHA-256: ca0a7b52aaa17353d8932e5c6e9b0a81c39aa6a2c46a691c73ba293b1863ac1a
font_02_sfnt_off0000f174.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF174 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1