Malicious PDF — malware analysis report

Static analysis result for SHA-256 274b7a4fd7e148e4…

MALICIOUS

PDF

69.1 KB Created: 2021-09-11 20:56:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8e88f2787424a54116cb0b7965d84536 SHA-1: 4eaddc45d558b44f7ace1802273217d73c06748e SHA-256: 274b7a4fd7e148e4ac1e663ec6a44159bed61df2363276f608f2c080e17a0ec9
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics indicate a deliberate attempt to create a link farm on potentially malicious or compromised infrastructure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or directing users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://philabc.ru/uplcv?utm_term=most+popular+fortnite+skins+2020 PDF link annotation
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/b311e977c17509cdd6e6103298acbe75/27945421797.pdfIn PDF document text
    • http://www.gesas.it/media/mailinglist/file/wogopizomuti.pdfIn PDF document text
    • http://tai-group.com/upload/files/79480795425.pdfIn PDF document text
    • http://upservice.expert/admin/ckfinder/userfiles/files/rupujisovafakexib.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/5af5ae9abc1382a0af9e42c0c540638a/nojifulok.pdfIn PDF document text
    • http://boldogelet.hu/media/pajedodagolupojodetopazi.pdfIn PDF document text
    • http://riverhouse.at/pcms/content/file/15755700447.pdfIn PDF document text
    • http://kmsenior.org/file/files/fidetope.pdfIn PDF document text
    • https://kibledergisi.net/resimler/files/raxanopapuridividodeguj.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/161328d8a4284a---96622103969.pdfIn PDF document text
    • https://triosms.com/userfiles/file/jigekikafumibadanugovew.pdfIn PDF document text
    • http://om-ar.com/userfiles/file/vozebidekabumevudu.pdfIn PDF document text
    • http://lianbang123.com/uploads/files/202109090659553119.pdfIn PDF document text
    • https://cobrawire.com/userfiles/files/webojomujin.pdfIn PDF document text
    • https://playindiano1.in/ckfinder/userfiles/files/92003163960.pdfIn PDF document text
    • https://smartmedia.ro/app/webroot/files/userfiles/files/metutugerunixukakefuxavo.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/36753217126.pdfIn PDF document text
    • https://sabresources.com/FCKuploads/file/sawojazipibojijibate.pdfIn PDF document text
    • http://harnettcountyhba.com/userfiles/file/41736287659.pdfIn PDF document text
    • http://355353.ru/userfiles/file/zegoxezabiwasomuxadulifab.pdfIn PDF document text
    • https://stcc-sa.com/motakamel/Ups/files/95588289111.pdfIn PDF document text
    • http://angel-conference.org/upload_fck/file/2021-9-11/20210911104805281018.pdfIn PDF document text
    • http://webinaris.blog/ckfinder/userfiles/publics/files/14196716644.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_off0000b052.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB052 15140 bytes
SHA-256: 4d53e3eb092bda641bb844ac716b9ad9a952e6c48cf93822ae720bd87873d20f
font_01_sfnt_off0000d651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD651 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE68 10780 bytes
SHA-256: 4a87bd353ea2cc7123d2462cf39553729dba790fc1d5ec40ab6b99cf9d1d77b6