Malicious PDF — malware analysis report

Static analysis result for SHA-256 3746845b8fc3c356…

MALICIOUS

PDF

78.8 KB Created: 2021-09-17 10:55:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8efad0b1498a7bf195712cc42a01b237 SHA-1: 12c9e369f86ee9b913f3762845ce9ca9fd958b48 SHA-256: 3746845b8fc3c3566e32fdc33181933f8ea180d0de193d58f4c6722fa2cab614
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and multiple external URIs, many of which point to compromised WordPress sites acting as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://laborke.ru/uplcv?utm_term=extreme+car+driving+simulator+new+update PDF link annotation
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161358a742d2a1---85115470377.pdfIn PDF document text
    • http://ke-sen.com/userfiles/file/1630619937.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161342a638e654---vavon.pdfIn PDF document text
    • http://handlpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/1958406006.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/38643995824.pdfIn PDF document text
    • http://nitecoreromania.ro/files/file/10810638221.pdfIn PDF document text
    • http://ngoinvest.com/uploads/ckfinder/files/puxotadasolo.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021091700251581189.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/xuduzivujelilox.pdfIn PDF document text
    • http://elma1.ru/!upload/files/lokokiwidulef.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16136f1c859c1a---wuvidovepibojolesepilod.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/13151276389.pdfIn PDF document text
    • https://kurashi-kyoiku.com/cms/dat/upimg/file/55459481340.pdfIn PDF document text
    • https://searchlink.org/userfiles/file/jefoxoni.pdfIn PDF document text
    • https://altaitur.com/ckfinder/userfiles/files/89984292391.pdfIn PDF document text
    • https://www.shamshabaddiocese.org/files/js/ckfinder/userfiles/files/vagedosolafogepiwebovizu.pdfIn PDF document text
    • https://dbmotorbrokers.com/userfiles/file/pitafunodoribepafozogolat.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/43173590521.pdfIn PDF document text
    • http://nattukoottam.com/userfiles/file/memevofipokomabinezaso.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16141ec554bf13---98317273175.pdfIn PDF document text
    • http://morethancars.nl/uploads/edytor/file/80997247811.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_off0000cf97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF97 17280 bytes
SHA-256: 61c3da7612009bad80f53893d2e62eb0534e6100b93e329b4ff759bb3d918d23
font_01_sfnt_off0000fb76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB76 11192 bytes
SHA-256: 78d7554dc85c848842d25997fb5a39c2d413c1796e78f3abebdf322b38deb0a3
font_02_sfnt_off00011586.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11586 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1