Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6728ea28aa6cfa2…

MALICIOUS

PDF

69.2 KB Created: 2021-10-01 02:16:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: f5c33108205872c006ed1af571a857a5 SHA-1: c400307016521acddaaa9097e438ffc1701cde61 SHA-256: a6728ea28aa6cfa298a02ff354ed7a522a8666cf90eeeb873bb05087442ba4eb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a high number of embedded URLs pointing to various domains, many of which are structured to resemble file downloads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests a tactic to obscure the true malicious destination by using numerous disposable domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://archism.ru/uplcv?utm_term=apk+wild+blood PDF link annotation
    • https://webmenuplus.com/images/file/ronifodirozibowos.pdfIn PDF document text
    • https://digbijoynath.in/uploads/userfiles/files/45859979966.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210918075310.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16136347f6f026---tojizewekaxetopukulezi.pdfIn PDF document text
    • http://win-sonic.com/ck_imgs/files/5778915385.pdfIn PDF document text
    • http://fueandhair.com/userfiles/files/seguruludi.pdfIn PDF document text
    • http://olech-rzeszow.pl/userfiles/file/rarunomapofapuxozatumuf.pdfIn PDF document text
    • https://micsys.in/userfiles/file/35044959543.pdfIn PDF document text
    • https://hondamienbac.vn/userfiles/file/70655149692.pdfIn PDF document text
    • https://selapro.com.au/application/third_party/ckfinder/userfiles/files/60697001579.pdfIn PDF document text
    • https://postelezmasivu-olomouc.cz/ckfinder/userfiles/files/42415625520.pdfIn PDF document text
    • https://kaptenhoki.com/contents/files/64682837833.pdfIn PDF document text
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/24609742434.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/favekasitisow.pdfIn PDF document text
    • http://phayaotechno.com/UserFiles/File/vivezewowoto.pdfIn PDF document text
    • http://pietroquatriniarchitetto.eu/userfiles/files/18493133762.pdfIn PDF document text
    • http://hzeiger.com/userfiles/file/wirafomegetajudo.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/navanubatixozojurazap.pdfIn PDF document text
    • https://goodline.by/userfiles/file/28065797463.pdfIn PDF document text
    • https://aihr-iadh.org/uploads/FCK_files/file/sidomoxiluzibakobir.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/repupudatixetiga.pdfIn PDF document text
    • https://daynexweb.com/upload/ckfinder/files/46159866170.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/f3a45ab8e17347b2d264e005628b16af/xatuji.pdfIn PDF document text
    • http://sjhrz.com/images/upload/File/27079954204.pdfIn PDF document text
    • http://changwontour.kr/FileData/ckfinder/files/20210920_8482B80B5EC36003.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_off0000b3d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cbea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBEA 9920 bytes
SHA-256: f16e6e39b36898818a41863937f0d57c2e5a2c7b7aa9a8b9074943cc716b148a
font_02_sfnt_off0000e19f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE19F 15024 bytes
SHA-256: 133350efa5dd5b80b2c927ac959e044aa42cf9ffb72808c50c93417117dca587