Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8853b8e3b7c1a33…

MALICIOUS

PDF

79.4 KB Created: 2021-09-23 22:52:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: feeab0a9577de1dd0af42640ef6188c5 SHA-1: 46b6a086b92dc4fe88a7b67300de6aae9af6d5de SHA-256: c8853b8e3b7c1a33c5eaffa76b50926d1afe90511391f30114e7bd0d862770b8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, suggesting a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of external URI heuristics and the sheer volume of URLs point towards a campaign designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 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://huntic.ru/uplcv?utm_term=yahtzee+score+sheet+pdf PDF link annotation
    • http://ottuk-e.org/userData/board/file/81101361159.pdfIn PDF document text
    • http://kmjmt.com/news/upload/file/2109011718513708383elcg9.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/161415af1e2af8---37453045518.pdfIn PDF document text
    • https://lamthong-marchph.com/piceditor/file/64523320696.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161433f163b257---pegenexenepakawowinero.pdfIn PDF document text
    • http://avon-bratislava.sk/files/files/fexonesubuxuluginoni.pdfIn PDF document text
    • http://gestioniarmatoriali.it/40839096616.pdfIn PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161306e053bd2d---kesaxatonamosu.pdfIn PDF document text
    • https://keluargamimpi2.com/contents/files/popetebu.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f78398d104---tojares.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/gupojezimod.pdfIn PDF document text
    • https://mbbs.hr/files/koxikozinideboviwiluju.pdfIn PDF document text
    • http://vswet.ru/f/29822395332.pdfIn PDF document text
    • http://holland-ex.com/images/blog/file/gapexokelaranatowomikal.pdfIn PDF document text
    • https://bhsbeacon.com/FCKeditor/file/bupodexetamigotazedegubo.pdfIn PDF document text
    • http://tylincms.com/userfiles/files/71802212508.pdfIn PDF document text
    • http://tzsunup.com/upload/24249825162.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/povinomobozidekinesom.pdfIn PDF document text
    • https://f27szerviz.hu/upload/files/15969447705.pdfIn PDF document text
    • http://kbcsisa.com/upload/fckeditor/file/bolopagu.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/zodobozevuru.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_off0000d331.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD331 10516 bytes
SHA-256: 0dfb74fcd245a14c4b9577450ed496ba1cbaddd339aa0fa0e8d934916533181c
font_01_sfnt_off0000eb55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB55 17356 bytes
SHA-256: 2b1054e357f3535f93c46d98c92ef5503ba0644da9c6fe94cbf6776c05e1623c
font_02_sfnt_off0001186a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1186A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1