Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b57d1fd801e865b…

MALICIOUS

PDF

87.9 KB Created: 2021-09-19 20:12:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 1f6da6157bc8f16234d6dcb5921d26bd SHA-1: cf7002426cbb62cce9b88c7a06c93dec26aa73cf SHA-256: 4b57d1fd801e865b12506ac7c69dd59fa154206146c93743f317bb47515164a1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to suspicious domains and are likely part of a link farm designed to obscure the true destination. The PDF structure and the presence of external URIs suggest an attempt to redirect the user to malicious content, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nousgarage.com/userfiles/file/retuzetudidavawewewe.pdf In PDF document text
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/q3uf1pmg6bpfmpvf5nna9vi2a3/kojudepirupuzapoxokeval.pdfIn PDF document text
    • http://elrey-uslugi.ru/media/file/85745221848.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/7741906582.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/78688339650.pdfIn PDF document text
    • http://www.louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/gowulemogukujozilov.pdfIn PDF document text
    • https://zniczekowalczyk.com/user_images/file/buxubudevu.pdfIn PDF document text
    • https://learningsolution.ca/userfiles/files/dilagitopebew.pdfIn PDF document text
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/94673274723.pdfIn PDF document text
    • https://edex.co/userfiles/files/xikomaridemolixedamarome.pdfIn PDF document text
    • https://likeevent.it/writable/public/userfiles/file/75660329388.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/76387311376.pdfIn PDF document text
    • http://khachsanmyngoc.com/upload/files/kapojitur.pdfIn PDF document text
    • http://fsgpj.com/upfolder/e/files/20210907110006.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/or0ptm3lc0laq6jtml1tgp3dbc/fevutazupanakamejozafam.pdfIn PDF document text
    • http://wefocusdesign.com/upload/files/84737763094.pdfIn PDF document text
    • https://krusomying.com/data/file/3784408060.pdfIn PDF document text
    • http://ccshecea.org/upload/files/wezajawego.pdfIn PDF document text
    • http://ediljolli.com/userfiles/files/15669691538.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/52505710024.pdfIn PDF document text
    • https://cpsguffanti.com/uploads/file/71318155125.pdfIn PDF document text
    • http://tele-klass.ru/i/upload/files/vigawobubenudojafapepuj.pdfIn PDF document text
    • http://ndfeef.com/radiant/mechimobiles/userfiles/files/82727287370.pdfIn PDF document text
    • http://ewhamd.net/upFiles/ckeditor/files/53333839519.pdfIn PDF document text
    • https://deltaguvenlik.net/userfiles/file/58027723160.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=android+secure+wifi+appPDF 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_off0000f389.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF389 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010ba0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BA0 10636 bytes
SHA-256: 3fd8a120f4f64ac6369e9123891289893ccf36314c73c352a7a1213f41ddfdef
font_02_sfnt_off00012427.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12427 17592 bytes
SHA-256: 5b8a76eda4b09b268b79e2d34bdb0b58d94e8e883e00d8046e206675e37b8fcd