Malicious PDF — malware analysis report

Static analysis result for SHA-256 a633deb8a0246228…

MALICIOUS

PDF

69.2 KB Created: 2021-09-13 22:01:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c39f102688cac929bc1295201c2f4049 SHA-1: 5865e44aea88d066551f4b75321eac0faa087b62 SHA-256: a633deb8a024622882fa498a98cf07744910215d626259f37f28d3b1d9d04c91
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was classified as malicious by ML and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to various domains, suggesting it functions as a link farm or redirection service. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, indicating a tactic to distribute malicious content or phish users. No scripts were extracted, but the presence of numerous external URIs is a strong indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://archism.ru/uplcv?utm_term=how+to+see+private+insta PDF link annotation
    • http://obraz-tlt.ru/userfiles/file/59521521139.pdfIn PDF document text
    • http://azco.friend-match.com/upload/files/21701873742.pdfIn PDF document text
    • https://5ky13lu3-1251.com/contents/files/xaborikokuxuxugivazuji.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/f479osrd09jso7651jb4m9tope/xijuzibitamokewoj.pdfIn PDF document text
    • http://bud-med.eu/userfiles/file/niduguwa.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/71388754568.pdfIn PDF document text
    • http://gamecoast.by/uploads/files/8567874311.pdfIn PDF document text
    • https://shivajigrihnirman.com/singhania/downloads/file/bupibi.pdfIn PDF document text
    • http://www.atccs3.it/atccs3/fckeditor/editor/ckfinder/userfiles/files/tinixotewa.pdfIn PDF document text
    • http://artechq8.com/beta/uploads/files/vewovez.pdfIn PDF document text
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/88724399457.pdfIn PDF document text
    • http://besteva.com/upload/files/bitolejesujogirezotaturej.pdfIn PDF document text
    • https://meganimal.pt/site/upload/file/sokirezik.pdfIn PDF document text
    • https://sahyadrisevasanstha.in/userfiles/file/neritovukotawefipuroja.pdfIn PDF document text
    • https://korzo-galeria.hu/files/file/60359034469.pdfIn PDF document text
    • http://bongoes62.dk/userfiles/file/lojilorarapuvesugaso.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/memivezo.pdfIn PDF document text
    • http://gadkowski.pl/repository/filemanager/file/mopekefo.pdfIn PDF document text
    • http://a1climbing.com/userfiles/files/28196830343.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16138e529bb9dc---68145150241.pdfIn PDF document text
    • https://nbretail.com.vn/ckfinder/userfiles/files/23513069042.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_off0000b192.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB192 10344 bytes
SHA-256: fb5dc707fa8f8072b57e123fb866d31124f17de9e4a1dadc20d6317f9c6cd1b2
font_01_sfnt_off0000c914.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC914 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e126.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE126 15348 bytes
SHA-256: 80827344c97df17424930fe58b6608ab053e115c915b0253392449b6082bc1ec