Malicious PDF — malware analysis report

Static analysis result for SHA-256 213bf23eeb0a531d…

MALICIOUS

PDF

70.9 KB Created: 2021-09-30 10:04:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e08523e33f50c29e089b595cb01528ae SHA-1: 671490a79749c1dbc187eac569259d9c48cc2e09 SHA-256: 213bf23eeb0a531d11b4751d678e0fcdbdabf1df653d9bb84b89f7910b25f357
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains embedded JavaScript and numerous external URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The primary function seems to be redirecting users to potentially malicious content, consistent with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://laborke.ru/uplcv?utm_term=adblock+free+extension PDF link annotation
    • http://odnoklassniki-files.ru/images/uploads/files/97478090615.pdfIn PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/lizerufelivusafaveluxo.pdfIn PDF document text
    • http://hk-keber.de/images/file/22774445820.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/c837cd12aeb396867a450c3db97c786a/12959013508.pdfIn PDF document text
    • http://plenaseguroseprevidencia.com/fotosempresa/files/fudarebebewi.pdfIn PDF document text
    • https://artemishosp-em.tw/uploads/files/202109221410201303.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613897ea8b66d---vakos.pdfIn PDF document text
    • http://navigator-nsk.ru/userfiles/file/4393511877.pdfIn PDF document text
    • http://daisin1977.com/js/upload/files/duwagezan.pdfIn PDF document text
    • http://yachtales.net/admin/userfiles/files/fawagokosupujozuwemewuva.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/bewabukozuzapejafevenafo.pdfIn PDF document text
    • https://eguiders.com/uploads/63784861626.pdfIn PDF document text
    • https://fuze-pay.com/ckfinder/userfiles/files/rewor.pdfIn PDF document text
    • http://back2wood.de/userfiles/file/somobake.pdfIn PDF document text
    • http://gapoom.com/upload/fckeditor/file/92444110615.pdfIn PDF document text
    • http://koreabulk.net/userData/board/file/50631625913.pdfIn PDF document text
    • https://www.weldcor.ca/public/ckfinder/userfiles/files/kodesiguxepikodabusi.pdfIn PDF document text
    • http://compagniaviaggi.gattinonimondodivacanze.it/themes/userfiles/files/xarimexorixamidujonibame.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/upuloromasimoruvuke.pdfIn PDF document text
    • https://pankajplast.com/ckfinder/userfiles/files/jarivikolorexejag.pdfIn PDF document text
    • http://akademibt.com/resimler/files/36381678869.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/buzobelofezak.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/vamavagigakumafameb.pdfIn PDF document text
    • http://xn--e42bt3l.net/upfile/files/90797704494.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_off0000b1d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1D5 10620 bytes
SHA-256: c59364386054bb872803e441189be7e945853b22178484c26baadb58ad99d11f
font_01_sfnt_off0000ca3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA3E 17200 bytes
SHA-256: 5c8822f1723503b565205192d9bafca7f604b2a09c5eac678352176891429f22
font_02_sfnt_off0000f640.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF640 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1