Malicious PDF — malware analysis report

Static analysis result for SHA-256 a195f5ef13166977…

MALICIOUS

PDF

87.0 KB Created: 2021-08-17 11:36:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a041f006f8920e3cc3652f0fce2a2c5d SHA-1: ac06cc036751302beb0a9b8d3d3ff322350fc628 SHA-256: a195f5ef131669777138302d17f16f5b8cc709c12f8eb3a7a16e49fe59a07372
156 Risk Score

Malware Insights

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

The sample is a PDF document that contains a large number of links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of a link farm on potentially compromised infrastructure suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606f37561e6d0---jimifugasun.pdf In PDF document text
    • http://kusadasidentalclinic.com/img/userfiles/files/geromivoruwa.pdfIn PDF document text
    • https://szud94.hu/img/sajatfile/files/46925741687.pdfIn PDF document text
    • http://afslab.asia/upload/files/55684528127.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160fcf7ab54763---16022649593.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/61679360742.pdfIn PDF document text
    • https://szekszardportal.hu/userfiles/file/81255547869.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/16109aec9ee79b---nuwavekilusopitonipiralu.pdfIn PDF document text
    • http://sheeld.org/clients/d/d0/d021426cee8527c21a172be12ef3d645/File/87818394446.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/160edaec5839d5---71621167800.pdfIn PDF document text
    • http://kppzp.pl/userfiles/file/xujodogojalego.pdfIn PDF document text
    • http://sunarfactory.com/userfiles/files/27050134995.pdfIn PDF document text
    • http://jinxinghotel.com/uploads/files/jalaxa.pdfIn PDF document text
    • https://thic.muki001.com/plugin/ce1/ckfinder/userfiles/files/77998682757.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/48379156723.pdfIn PDF document text
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/16070814151d4b---jogidefutivelizexoboseka.pdfIn PDF document text
    • https://hometeamcorp.com/images/usr/sobejuzawututekuve.pdfIn PDF document text
    • http://szymonadamczyk.pl/uploads/fck/file/71181440139.pdfIn PDF document text
    • https://etre-cheval.fr/Applications/MAMP/htdocs/etre%20cheval/news_pix/file/33158960929.pdfIn PDF document text
    • https://rachelrom.com/rescontent/file/jelijizonijanadudubep.pdfIn PDF document text
    • http://hoaisonland.vn/upload/files/63059602159.pdfIn PDF document text
    • http://silesiacapital.eu/data/file/29098142032.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b7bd4a5cff8---jisujuw.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/o1qehn34bgjk85vb0tdpvpmdjb/29339872547.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=how+to+use+verizon+mobile+hotspot+for+freePDF link annotation
    • 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_off0000ef43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF43 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001075a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1075A 10904 bytes
SHA-256: 3d3daaaee38bab4e003a854fce002b76c737ebd9d5137e74280c7ad5033ae5a8
font_02_sfnt_off0001202c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1202C 17224 bytes
SHA-256: d2098cf6daf4acac64a05af1d4c39e896dc6fa159a129823b2888d99e5affa54