Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6dc23eb419cb60d…

MALICIOUS

PDF

71.3 KB Created: 2021-09-20 23:02:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fe5e1ee206e59376746b52a6cc2f9fe6 SHA-1: 13a2ec317320161f3f9fc95a1268725bcde02651 SHA-256: a6dc23eb419cb60d72bdd503ec0be7fd6b6434e03025b853febdeb4693e6a9ac
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier returned a high probability of maliciousness. Heuristics indicate it functions as a link farm with numerous external URLs, suggesting a phishing or malware distribution attempt. The document body is unreadable, but the presence of many distinct hosts and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://uzmanwebci.com/calisma2/files/uploads/17701871102.pdf In PDF document text
    • http://exteractif.fr/pictures/2/kufutazekiregoxudabigum.pdfIn PDF document text
    • http://vanlysecurity.vn/vanly/album/files/39974273544.pdfIn PDF document text
    • http://www.supair-lux.hu/ckfinder/userfiles/files/lobasigefexolaj.pdfIn PDF document text
    • http://jatechkj.pl/upload/fck/file/rogetunojomilizizo.pdfIn PDF document text
    • https://aeternoplanning.com/ckfinder/userfiles/files/mizaz.pdfIn PDF document text
    • https://tmtteks.com/files/karimixip.pdfIn PDF document text
    • http://harryreichert.de/uploaded_pics/News/file/55965682462.pdfIn PDF document text
    • http://prime42.ru/userfiles/files/niroka.pdfIn PDF document text
    • http://bona-agra.pl/Upload/file/53071170171.pdfIn PDF document text
    • http://gamjagolla.com/uploads/files/60490411171.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/libejipuv.pdfIn PDF document text
    • https://www.groupe-coelho.fr/ckfinder/userfiles/files/ludovazawinusevijasad.pdfIn PDF document text
    • http://generoussecurity.com/uploads/tabig.pdfIn PDF document text
    • https://rolcsi-bau.hu/userfiles/files/wobumuzezoxusukeditekew.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/sewuporowajugobigixixejeb.pdfIn PDF document text
    • http://teresachild.com/upload/files/51961883292.pdfIn PDF document text
    • http://matrix-corporation.com/upfiles/editor/files/setus.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7bc3385ab---68368988295.pdfIn PDF document text
    • http://adec-interiors.net/Uploads/file/mubeza.pdfIn PDF document text
    • http://abpjse.news-read.com/upload/files/zosogurezusugolazirokoti.pdfIn PDF document text
    • https://www.winsum.frl/ckfinder/userfiles/files/zaroxopofimunipax.pdfIn PDF document text
    • http://maristaslardero.es/userfiles/file/92702407146.pdfIn PDF document text
    • http://evolutionchonburi.com/userfiles/files/35817143070.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132d89b8ebd7---detokegibe.pdfIn PDF document text
    • https://valenciamaids.com/userfiles/files/zofatugirenuvodesixado.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=compliments+beginning+with+cPDF 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_off0000b821.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB821 15100 bytes
SHA-256: f78a3cc687638845f13b956cf04b7591ac198765409243a7b33b7bda6110ec0b
font_01_sfnt_off0000de6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE6F 10816 bytes
SHA-256: be1e618d4dc30e77a9b04645231054302f0dd164b4bd06d7d5d12405bf61b812
font_02_sfnt_off0000f705.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF705 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1