Malicious PDF — malware analysis report

Static analysis result for SHA-256 9fef1c89a4cab543…

MALICIOUS

PDF

86.1 KB Created: 2021-06-26 16:00:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: d195665462e63e7b697b11626847f5a8 SHA-1: c9b856f3ca94c706494c434231708dcc53f545c7 SHA-256: 9fef1c89a4cab543828d8286acafa565c7cd633c90a4ba3afa6294074c944266
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links to external resources, many of which point to compromised WordPress sites hosting other PDF files. This behavior is indicative of a link farm designed to redirect users to malicious content, likely for phishing or malware distribution. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://wastran.ru/uplcv?utm_term=words+that+start+with+z+and+end+with+c PDF link annotation
    • https://thuaphatlaihanoi.net/uploads/files/nonabetuxopamiz.pdfIn PDF document text
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/8g6ln4u3chch1tci0n7u058htt/64340748006.pdfIn PDF document text
    • https://susta.vn/userfiles/file/zasisiwevovumifekepavesu.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607606755738a---nixegotudatakoso.pdfIn PDF document text
    • https://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/f9kfm5ej6vemq8tes0erap3kms/tomilojo.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160b559f3bf5d0---malirufova.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1608dbb2e723b7---sepuza.pdfIn PDF document text
    • https://nazragame.com/calisma2/files/uploads/mimedo.pdfIn PDF document text
    • http://vodnik48.ru/content/file/2193608047.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/gr9m46h71rdutin3fbtld2o9s9/sozegatedadisilori.pdfIn PDF document text
    • https://diedacorporation.net/freesiafiles/file/14124268755.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/748s3c5crp7kgt3kebdbd6us04/41756075750.pdfIn PDF document text
    • http://bangdinhphucat.com/quangbasanpham/app/webroot/upload/image/files/29158916547.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adb7f20dc23---sobolopikogakavime.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/59462005801.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8a6144551---vozotujofuz.pdfIn PDF document text
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/f60cb733a54c757374bbfc139ddf1ff4/67147120289.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbe7117b9a0---nirawixubud.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/2628f12f86dd7d015e5d74aaf1f09098/80409460768.pdfIn PDF document text
    • http://hondaotohaiphong.vn/upload/files/sifizorapujuwigugonipan.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5787770fb08496944294b2fc47e77126/wesojobirilemupo.pdfIn PDF document text
    • https://valleyrestoration.net/home/apf/public_html/ckfinder/userfiles/files/77361838897.pdfIn PDF document text
    • https://hrmconsulting.biz/upload/files/voxavefi.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_off0000ec71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC71 17576 bytes
SHA-256: c21d7d581a004233e46e70b0047514b85f93a3b117233526972ebaf2502e4b31
font_01_sfnt_off00011a8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A8B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000132a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132A2 10560 bytes
SHA-256: 25e8b09800fe60fabc123d2804653315a4509973db7a3ace20fbe43e66c270f0