Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4708048fd43f7a1…

MALICIOUS

PDF

67.8 KB Created: 2021-09-28 15:54:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 7f5cfed8387eef8890328116cdccf228 SHA-1: a4c4b2b97b88adadb23f034e97bad6eb6e3471cf SHA-256: b4708048fd43f7a19c0ad192af8f6eada1bf7214359b51c1d17bc287568f6315
166 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to other PDF files hosted on disposable domains, indicating a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the nature of the links, suggesting a tactic to evade detection by distributing malicious content across many low-reputation domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://drafthe.ru/uplcv?utm_term=baya+marathi+magazine+pdf PDF link annotation
    • https://boumqueur-edition.com/upload/fckeditor/file/furisovixeri.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-9-20/20210920010705629252.pdfIn PDF document text
    • https://losaltos.com/wysiwygfiles/file/vojovefo.pdfIn PDF document text
    • http://dotacjedlaoze.pl/userfiles/file/balidapudolitalikawage.pdfIn PDF document text
    • http://www.kymkarajok.net/tiedostot/files/vegipadinesasiz.pdfIn PDF document text
    • https://internationallanguagenavigators.com/media/27753231508.pdfIn PDF document text
    • http://24cvety.ru/upload/files/61880484006.pdfIn PDF document text
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/renar.pdfIn PDF document text
    • http://bjqyms.com/filespath/files/20210907195113.pdfIn PDF document text
    • http://oshcongregation.com/userfiles/file/57560287871.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/vewero.pdfIn PDF document text
    • https://bnovum.hu/downloads/divepevovidu.pdfIn PDF document text
    • https://dascalita.ro/app/webroot/files/userfiles/files/lukukat.pdfIn PDF document text
    • http://seatraveltx.com/uploads/files/xekovamijut.pdfIn PDF document text
    • https://ipssecurityconsultants.com/ckfinder/userfiles/files/ximofujivejeledug.pdfIn PDF document text
    • http://hyeminshop.com/DATA/files/pinuruvukofinijodusadaxi.pdfIn PDF document text
    • https://avphunter.ro/ckfinder/userfiles/files/baxakaziboxubijefofevo.pdfIn PDF document text
    • http://el-master.ru/userfiles/file/votakaxafomototupup.pdfIn PDF document text
    • http://natpuedu.in/userfiles/file/89641794460.pdfIn PDF document text
    • http://tinhotsaigon.com/uploads/files/75657253669.pdfIn PDF document text
    • https://bloomland.com/sites/bloomland.com/files/zulekojumekikafavavetuse.pdfIn PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16148279c4ab27---54084999688.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_off0000ac7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c48e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC48E 14660 bytes
SHA-256: 8e386695060264e704afe901502ccbb948879bca8722e1f6e9df03af93a3777b
font_02_sfnt_off0000e993.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE993 10836 bytes
SHA-256: b02ef007049107615013e1d90a61ccf98d4d04108c55b5e79d8bfbf7edcf50b4