Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8760d2ec4391855…

MALICIOUS

PDF

88.5 KB Created: 2021-10-05 09:59:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 3f84a004001663df834c22239ad6eda2 SHA-1: 7246f903c0d6e93cc3ae42ea359b48db036a5a50 SHA-256: a8760d2ec43918553126c18970fb5a62124eeb9aac29289ed4948e6dba6ad511
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which appear to be part of a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for executing malicious code within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

Heuristics 6

  • 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.
  • 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://medvor.ru/uplcv?utm_term=how+to+export+pdf+photoshop PDF link annotation
    • http://slabowidzacy.smprzemysl.pl/ckfinder/userfiles/files/25401401026.pdfIn PDF document text
    • http://ongxoanhdpe.vn/upload/files/41702031311.pdfIn PDF document text
    • https://r4binsh4h9-att.com/contents/files/89770264125.pdfIn PDF document text
    • http://szyuangang.com/UserFiles/file///80978636280.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/72945890725.pdfIn PDF document text
    • https://consultemergingmarkets.cubsindia.com/files/51580292229.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16147dd64854e9---tabakubegaxanurewosapod.pdfIn PDF document text
    • https://cafeau1ait.xyz/js/ckfinder/userfiles/files/68030017381.pdfIn PDF document text
    • http://le-bouquet.be/userfiles/files/lilogajipu.pdfIn PDF document text
    • http://obedovice.cz/userfiles/file/jasumufetoturi.pdfIn PDF document text
    • http://speed-r.com/js/upload/files/lexaxajizafir.pdfIn PDF document text
    • https://erdenetpost.mn/userfiles/files/gavalolotij.pdfIn PDF document text
    • http://qdjshg.com/files/file/jusop.pdfIn PDF document text
    • http://pmke.cz/pictures/files/76484313623.pdfIn PDF document text
    • https://claudiodituri.it/uploads/4110497002.pdfIn PDF document text
    • https://enilubricantvn.hoakhanh.vn/uploads/image/files/77468142838.pdfIn PDF document text
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/62547901846.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/84104206884.pdfIn PDF document text
    • https://red-adlay.com/upload/files/pujaredebuzabekivutim.pdfIn PDF document text
    • http://mosme.org/uploadfile/files/81924546149.pdfIn PDF document text
    • http://ck-kutnahora.cz/gais/image/file/jubidigudeboziguniregon.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1631948885.pdfIn PDF document text
    • http://changjiujz.com/uploads/files/202109010919388394.pdfIn PDF document text
    • http://portalkucharski.pl/app/webroot/media/files/xedopovabogexetepi.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161542386843e7---vibosajogasu.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_off0000f369.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF369 19096 bytes
SHA-256: 235255500cfd65f06ae7b470530be6eeaf605c24be2b1e765571454e56bf4c95
font_01_sfnt_off000124f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124F3 10372 bytes
SHA-256: 497bc3bd286af37787d1e473cb5c3956eb93174647a6dca696d1ee4d640c2204
font_02_sfnt_off00013c91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C91 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1