Malicious PDF — malware analysis report

Static analysis result for SHA-256 9611b73bad6621fd…

MALICIOUS

PDF

82.7 KB Created: 2021-09-21 06:53:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 092f773f301f1caa41814d42cd9131a8 SHA-1: 0a45259947542621fd27a98eb15500aae300c21f SHA-256: 9611b73bad6621fdad2c31b6ccaecff6667b9f999be647da8bcc07bed82988c7
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with high-severity heuristics indicating a PDF linking to algorithmically-generated URLs. The document body is heavily obfuscated, but the presence of external URIs and link farm characteristics suggests a lure to external malicious content. The primary attack pattern involves directing users to a malicious PDF hosted on a potentially compromised or disposable domain.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://infrive.ru/uplcv?utm_term=no+dress+photo+editor PDF link annotation
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/161366d8ea19c7---pulikisanuxuva.pdfIn PDF document text
    • http://pilot-market.ru/new/files/file/67555806998.pdfIn PDF document text
    • http://zekejozsef.eu/FCKfeltoltott/file/jakabitiduriju.pdfIn PDF document text
    • http://www.pibmg.com.br/ckfinder/userfiles/files/files/wiwefasozofinepotorib.pdfIn PDF document text
    • http://www.nomorcantikjoss.com/file/puwosuzumeluzexarobogar.pdfIn PDF document text
    • http://yongqingtech.com/d/files/fudomaguwe.pdfIn PDF document text
    • http://recuva.kr/upload/fck_img/1630755148/file/weminipap.pdfIn PDF document text
    • http://halongbaycruises.org/upload/files/nebiviwuw.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///nixijurokakonomenuridatiz.pdfIn PDF document text
    • https://marbletreasures.com/uploads/image/files/noxogalixomaxidefopu.pdfIn PDF document text
    • http://julianina.dk/upload/file/wosefug.pdfIn PDF document text
    • http://arsvet.ru/img/upload/95584251088.pdfIn PDF document text
    • https://internationallanguagenavigators.com/media/xavib.pdfIn PDF document text
    • http://hainfelderteich.at/gonakigaxebabibunove.pdfIn PDF document text
    • http://gerd-pollak.de/userfiles/file/fijegodagevororab.pdfIn PDF document text
    • http://ranaghatpchsschool.org/userfiles/file/sisoxudigedexuvafa.pdfIn PDF document text
    • https://bankubezpieczen.pl/userfiles/file/soduz.pdfIn PDF document text
    • https://hargagila.com/uploads/image/files/pudemivadod.pdfIn PDF document text
    • http://jpsacademy.com/slbdavbatala/userfiles/file/49148300496.pdfIn PDF document text
    • https://cancelaria.pl/galeria/file/17617108814.pdfIn PDF document text
    • http://ipmarketing.net/FCKeditor/editor/filemanager/connectors/userfiles/file/sogidolunezemi.pdfIn PDF document text
    • http://www.mmd.ntou.edu.tw/ckfinder/userfiles/files/96063031441.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bda67e0514---91934616249.pdfIn PDF document text
    • http://udmvdpo.ru/images/files/nijazapiner.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_off0000e0e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0E5 10156 bytes
SHA-256: 5ee4de552cdb105dc16a0f87fa0f81e257b353e26b4217366cb6f0fe63eb7064
font_01_sfnt_off0000f7b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010fca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FCA 17532 bytes
SHA-256: 8d12ab1c4a19db22b0d60867e302dc925a0093d0d5c0896c2be84dea09c64025