Malicious PDF — malware analysis report

Static analysis result for SHA-256 4148de2d0b344433…

MALICIOUS

PDF

81.2 KB Created: 2021-09-11 11:19:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 168efa70cd50c1bb71fc7ef9aa7da2dd SHA-1: 9805db84f977823a15a86e000c5078defbda74fa SHA-256: 4148de2d0b344433278a7c5123c9cb1228f1021f8355d9b89aa157fa1f07f4b9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. It also features a link farm pointing to multiple domains, including one hosted on a compromised WordPress upload directory, suggesting an attempt to distribute further payloads or conduct phishing. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://synerhu.ru/uplcv?utm_term=what+is+the+fifth+largest+country PDF link annotation
    • http://torby.kbo.pl/ckfinder/userfiles/files/87051424158.pdfIn PDF document text
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210908_142035.pdfIn PDF document text
    • http://sun-green.nl/ckfinder/userfiles/files/kajosawenowaxegaza.pdfIn PDF document text
    • http://warwick-ems.org/userfiles/file/86973318674.pdfIn PDF document text
    • http://soloparamideco.com/js/new/fckeditor/userfiles/file/pimugivukogafewatipufavag.pdfIn PDF document text
    • http://ohadalegistrocbarter.com/ckeditor/uploads/files/wawuputobetaramuv.pdfIn PDF document text
    • https://pastelbuilders.com/userfiles/file/gijut.pdfIn PDF document text
    • http://takramaipai.com/mypicture/file/78725628043.pdfIn PDF document text
    • https://enerjimakine.com/tsrm1/img/userfiles/file/seluriru.pdfIn PDF document text
    • https://next-engineering.com/userfiles/files/58305042145.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/1c52a53dc5aa74353eee253123750e3d/sexulitevaritifegakuguri.pdfIn PDF document text
    • http://musicincw.com/fckeditor/userfiles/image/xokewajunifadekoxowod.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16132d27c41347---36439475220.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab933a4c85---73368979802.pdfIn PDF document text
    • http://veoguidecostarica.com/ci/userfiles/files/dojome.pdfIn PDF document text
    • https://tekdalyapi.com/upload/ckfinder/files/38785594901.pdfIn PDF document text
    • http://ytlcases.com/userfiles/file/vatuzebigogosegibovagu.pdfIn PDF document text
    • http://pescepiana.eu/userfiles/files/25399774782.pdfIn PDF document text
    • http://gzbaosui.com/uploadfile/files/25283446302.pdfIn PDF document text
    • https://karlschool.org/uploads/files/202109071125263451.pdfIn PDF document text
    • http://centromp.it/userfiles/files/zedur.pdfIn PDF document text
    • https://bloomeng.com/uploads/fujunajotilitajemeki.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_off0000d6f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6F8 18280 bytes
SHA-256: 3cf232fadaa01a73469514f79243311ec94b9b0528468a8dfd9170dcbf7333cd
font_01_sfnt_off00010623.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10623 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E3A 10824 bytes
SHA-256: 3d6c1e037ba157aaaba19b5c68da0c47e7cd73f8b58145d5b0f2173797f6d4c9