Malicious PDF — malware analysis report

Static analysis result for SHA-256 d979b0019b51b3d4…

MALICIOUS

PDF

81.9 KB Created: 2021-09-23 23:59:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 74df4c5022264fc0055cc00b76731895 SHA-1: 60e5c0d4eaeffce890d173e41f66806895ad0e26 SHA-256: d979b0019b51b3d4afb0b66575aef349f27935f94a9a54f4b9f8ad1593338c63
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised CMS uploads. The document body is heavily obfuscated and unreadable, but the presence of numerous external URLs, many hosted on potentially compromised sites, suggests a distribution or redirection mechanism. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://onderhoudnlgarantie.nl/upload/file/tibuminawuvitakenuzive.pdf In PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/8400498acec4629922ddae3e83c91391/78107107780.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/valuduzegumepixexadexofu.pdfIn PDF document text
    • http://autodilykanka.cz/cmsimple/images/file/61516440303.pdfIn PDF document text
    • http://80tner.friend-match.com/upload/files/wojamiguledow.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1614c39074c8bc---koribi.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138aa7251708---5917379778.pdfIn PDF document text
    • http://kaitianjinghua.cn/admin/userfiles/file/202109200546050917.pdfIn PDF document text
    • http://zmz72.ru/files/file/27794571010.pdfIn PDF document text
    • http://czminghe.com/upload/files/tulosavukuvotugekebifoji.pdfIn PDF document text
    • http://ergakiland.ru/files/files/funexamizerekidozikig.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/mubetalilekuvo.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/29615113668.pdfIn PDF document text
    • http://sowa-architekci.pl/userfiles/files/zevuv.pdfIn PDF document text
    • https://skatrip.com/basefile/skatripcom/files/riwajenu.pdfIn PDF document text
    • http://placc.info/up_image/wolujetafujurasezaw.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/bebimokefororovemoje.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/57189643370.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/wenoji.pdfIn PDF document text
    • http://hzxf.com/images/upload/File/nagokatov.pdfIn PDF document text
    • https://ezokniga.com/uploads/file/86876911850.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/96312756803.pdfIn PDF document text
    • http://ukrainski-rosyjski.pl/userfiles/file/22260190505.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/aa262be5666d3bbffaccb91fcb0fe5c7/jevugowosamadusakozuvuxe.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/volesazujemizadebon.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=how+to+share+screen+from+phone+to+tabletPDF 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_off0000dbfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f40d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF40D 17288 bytes
SHA-256: 63c9c057c3383157e36391052ffa90fab34f41ad90704bdb7a26e069f649af26
font_02_sfnt_off000120f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F7 10872 bytes
SHA-256: 26d8e6639c77a730432df42d90fe3f7e2d59e61bd92e457c643754c0db92bf26