Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a939117e83b8fe5…

MALICIOUS

PDF

72.8 KB Created: 2021-09-12 05:02:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: c38e79dd3e50e2ce20d38cb6bb819f2a SHA-1: 97d35850c9fb50c155f15bb9b833dd268bcb1fb2 SHA-256: 8a939117e83b8fe5abe636abe7b447c63d2468e199139b0d1e4b064b5160e2e7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, indicating it functions as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the ML classifier 'ML_NYX_PDF_MALICIOUS' strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the nature of the PDF and its numerous external links point towards a spearphishing attachment delivery vector.

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 https://smidgel.ru/uplcv?utm_term=funny+halo+gif PDF link annotation
    • https://desco.scp.hr/files/depemakonafivurinivinuk.pdfIn PDF document text
    • https://maribon.net/app/webroot/files/userfiles/files/giravidigalutujefolubi.pdfIn PDF document text
    • https://llibreriaha.com/img/events/file/6300747023.pdfIn PDF document text
    • http://nenkin-t.com/upload_img/ck/files/mozazemutupoxiviwobeboji.pdfIn PDF document text
    • http://slovbau.sk/test/userfiles/file/61900019675.pdfIn PDF document text
    • http://branonperformance.com/ckfinder/userfiles/files/ruxiko.pdfIn PDF document text
    • http://zbirozskepodzamci.cz/userfiles/1281000911.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/b80502354244bce862026e54da78ca79/7025658777.pdfIn PDF document text
    • https://subded.org/userfiles/file/25408618677.pdfIn PDF document text
    • http://drprdesaihospital.com/uploads/nexeruludimo.pdfIn PDF document text
    • https://huaienclinic.com/uploadpic/files/nidefel.pdfIn PDF document text
    • http://keifo.ru/ckfinder/userfiles/files/5867807446.pdfIn PDF document text
    • http://chinajessie.com/seadata/data/uploads/img/file/163084790719.pdfIn PDF document text
    • http://maradonasalud.com.ar/ckeditor/ckfinder/userfiles/files/40676939355.pdfIn PDF document text
    • http://pizzeriagiganti.ro/imagini_ws/63297659836.pdfIn PDF document text
    • http://bamboomfi.com/htdocs/cljr/data/files/mavikamurumopemodi.pdfIn PDF document text
    • http://arablift.net/userfiles/file/vedoj.pdfIn PDF document text
    • http://drcleancenter.com/uploads/files/202109100038387691.pdfIn PDF document text
    • http://cl-pub.com/files/files/63243939551.pdfIn PDF document text
    • http://msiutilities.biz/documents/82037684482.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library/File/28000273074.pdfIn PDF document text
    • https://mimpiindah2.com/contents/files/febemuvuwewotoxobikozeke.pdfIn PDF document text
    • http://flamefitnessstudio.com/cewit/images/file/medad.pdfIn PDF document text
    • http://botaierpharm.com/upload/files/85036054796.pdfIn PDF document text
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/wemoduf.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://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_off0000b96f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB96F 10184 bytes
SHA-256: 50d90f73b3640d256af315856935bcb06bb27bc8cad8f9f6c7a94ba9df349f82
font_01_sfnt_off0000d018.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD018 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e82a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE82A 17284 bytes
SHA-256: 81701c4f3b3c6fa6ce583820e9b04f4376dd4540ee41536676ded3447952dfb7