Malicious PDF — malware analysis report

Static analysis result for SHA-256 23539f4a48dc1a5a…

MALICIOUS

PDF

74.0 KB Created: 2021-09-16 13:20:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 620ab0eeed093761fad825773b4564df SHA-1: 9e276015356f34b9671ec3771e8a9a5f15c011ec SHA-256: 23539f4a48dc1a5a804e4e7da562ab4339820370a8be7485d0e685ac405a3f69
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript, which is often used to redirect users to malicious websites. The file also exhibits characteristics of a link farm, with numerous URLs pointing to potentially compromised or disposable hosting, suggesting an attempt to distribute malware or conduct phishing. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • 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://cructi.ru/uplcv?utm_term=rick+et+morty+vf+streaming PDF link annotation
    • http://bridgestone-ice-cruiser-7000.ru/ckfinder/userfiles/files/lajuwesatuxuzavepekewosar.pdfIn PDF document text
    • http://immobilieninvestors.org/userfiles/file/22637170130.pdfIn PDF document text
    • http://wamer.org/userfiles/file/33066178205.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612f644155a53---93584432549.pdfIn PDF document text
    • http://henskeschildersbedrijf.nl/upload/furazalutodisogi.pdfIn PDF document text
    • http://timeyear-v.com/userfiles/file/41575260031.pdfIn PDF document text
    • http://kientrucphatloc.com/upload/files/44889050619.pdfIn PDF document text
    • https://estoniapools.com/contents/files/tegabilopinapajowefuvezis.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/16131d7e578d58---71705045696.pdfIn PDF document text
    • http://paintmaster.hu/js/ckfinder/userfiles/files/94126396587.pdfIn PDF document text
    • https://manhremhoangvan.com/wp-content/uploads/files/vodedalejukesunozuz.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/55380575067.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c00a443837---wazokawu.pdfIn PDF document text
    • http://vnos.vn/app/webroot/uploads/files/sasojolewuderesuzo.pdfIn PDF document text
    • http://www.macrolepidoptera.hu/userfiles/files/tajumivetikunuxu.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/zaluwepozenotaxudodotipa.pdfIn PDF document text
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/fomegadup.pdfIn PDF document text
    • http://russkiivopros.com/images/FCKeditor/file/69856000634.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/c11cf5b396be0d5516e3efae1ed4cb86/53921778252.pdfIn PDF document text
    • https://mabuksusu2.com/contents/files/detuviweme.pdfIn PDF document text
    • https://boucherienabli.com/uploads/FCK_files/file/gadubelilebuvuw.pdfIn PDF document text
    • http://alessandrobelleseveterinario.eu/userfiles/files/95348645813.pdfIn PDF document text
    • http://ipceurope.be/assets/file/51997439869.pdfIn PDF document text
    • http://dailycan.com/userfiles/files/fegupividagojupogasumed.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_off0000bd1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD1F 10952 bytes
SHA-256: 6fa172e30cf252e73951642e964092e74deee5e1dacf1efbaf0b927e6e6289ed
font_01_sfnt_off0000d69f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD69F 17072 bytes
SHA-256: 7299fbefcd42bd6e2af1b3058e6d672f9f15636c2177853d08659995222b3f29
font_02_sfnt_off00010261.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10261 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1