Malicious PDF — malware analysis report

Static analysis result for SHA-256 54c8f6f2956067c4…

MALICIOUS

PDF

75.0 KB Created: 2021-10-04 03:20:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 9a9419c44df5c4e37a4ac05df8c723e2 SHA-1: daf943b8abff59dbabd08046987678d2763d2394 SHA-256: 54c8f6f2956067c424ac6a761606b52d14a18c590513c764d75530f4e1cd6aa6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ML classifiers and ClamAV, indicating a high probability of malicious intent. The PDF contains numerous embedded URLs, with a significant number pointing to domains that appear to be part of a link farm designed to obscure the final destination. One heuristic specifically identified the PDF as a 'DISPOSABLE_LINK_FARM', suggesting its primary purpose is to redirect users through multiple hops, likely to a phishing page or a malware download site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

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 http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/161581b7815ff9---47789379412.pdf In PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/db8b5468a429f78c5a9a866650ee30d2/36004388138.pdfIn PDF document text
    • http://xn--2-140-swe8h.xn--p1ai/files/kuripewerakigilutosed.pdfIn PDF document text
    • https://mediaskills.rs/files/80802320153.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/wepajevula.pdfIn PDF document text
    • https://shreenatharcade.com/userfiles/file/vagegijoru.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/11640381062.pdfIn PDF document text
    • http://lexxyin.net/files/fckeditor/file/fisubege.pdfIn PDF document text
    • https://coil.hk/upload/files/34919526392.pdfIn PDF document text
    • http://ahzycw.com/upload_fck/file/2021-9-4/20210904184710723863.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/gexumemowagajazuvodut.pdfIn PDF document text
    • http://citranco.com/users/files/rifazejuzatog.pdfIn PDF document text
    • http://familiegravesen.dk/ckfinder/userfiles/files/lubexaduguwozaze.pdfIn PDF document text
    • https://jpjplumbingandheating.com/FCKeditor/file/26787038638.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/pexixeken.pdfIn PDF document text
    • http://tingchucontrol.com/Uploadfiles/files/besalibuxisenixewedew.pdfIn PDF document text
    • http://www.aunay-sous-auneau.fr/ckfinder/userfiles/files/xavez.pdfIn PDF document text
    • http://autoservizimensi.it/images/fck/file/18712137410.pdfIn PDF document text
    • https://losaltos.com/wysiwygfiles/file/94434682242.pdfIn PDF document text
    • https://www.whoamiandwhyamihere.com/ckfinder/userfiles/files/50192023089.pdfIn PDF document text
    • http://fukaofoods.tw/uploads/files/202109171751554675.pdfIn PDF document text
    • https://muacash.com/webroot/img/files/lodinatof.pdfIn PDF document text
    • https://karthikaspices.com/uploads/file/46744081930.pdfIn PDF document text
    • http://sintniklaas.kinderopvangpimpeloentje.be/ckfinder/userfiles/files/paloposilale.pdfIn PDF document text
    • http://hotelclinton.it/userfiles/files/70082775144.pdfIn PDF document text
    • http://cokhiminhhien.com/media/ftp/file/gubijabififozewobikumifa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=find+the+greatest+number+that+will+divide+43+91+and+183PDF 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_off0000b9e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9E6 18888 bytes
SHA-256: 34755beb07d85c2dde9d6f66dd1182bae75bb62b08e2b80f9b25d5cd81c64057
font_01_sfnt_off0000ea49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA49 11624 bytes
SHA-256: 6479f496439680e2c0d784a32c9f514d15a4abb954816d41e45c007a953d7147
font_02_sfnt_off000105a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1