Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c8f87dbe950c9f8…

MALICIOUS

PDF

97.4 KB Created: 2021-09-08 23:31:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c172bad6601a7309ba3590ad67f77418 SHA-1: eb7087525a0d5ab31c48cb1554e37f07d486c7cd SHA-256: 1c8f87dbe950c9f8b5d2afa5ce4ec54d90176b229436ec29687a22fe2f01c410
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning model assigned a high probability of maliciousness. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, some hosted on compromised WordPress installations. The presence of numerous URLs, including those with UTM parameters, suggests an attempt to direct users to potentially malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9930

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://laborke.ru/uplcv?utm_term=on+screen+b1%2B+student%27s+book+answers PDF link annotation
    • http://karinameal.com/imgdish/files/batepadalijeg.pdfIn PDF document text
    • http://dealershop.es/camarasegovia/userfiles/file/52260965767.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16131f37fbcb18---kokusazeranorananixanur.pdfIn PDF document text
    • https://machnik.net/ckfinder/userfiles/files/81121338406.pdfIn PDF document text
    • http://gearonlaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fupagozevof.pdfIn PDF document text
    • http://toanlinh.vn/upload/files/zotulepasate.pdfIn PDF document text
    • https://edex.co/userfiles/files/64362367578.pdfIn PDF document text
    • https://sergiomauri.com/images/file/zunik.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1612eede7914d0---84856969122.pdfIn PDF document text
    • http://centromp.it/userfiles/files/56606072695.pdfIn PDF document text
    • http://studiotecnicobergamaschi.it/userfiles/files/poxuf.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135a193a9921---99248721621.pdfIn PDF document text
    • http://novichiha.ru/pic/file/fogojij.pdfIn PDF document text
    • http://angelescare.com/userfiles/file/kesufazasuno.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/noferoviligawajadufiru.pdfIn PDF document text
    • https://maxlinder.com/admin/assets/ckfinder/userfiles/files/87485687397.pdfIn PDF document text
    • https://blsautomation.com/ckfinder/userfiles/files/mokuvamovakutuzeluginap.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613618c0c1f17---96034313919.pdfIn PDF document text
    • http://mastera-mix.ru/ckfinder/userfiles/files/37091450549.pdfIn PDF document text
    • http://miyozenemeryville.com/uploads/files/madutagarive.pdfIn PDF document text
    • http://worshipedia.mobi/sites/default/files/file/kadabogoz.pdfIn PDF document text
    • http://lednotice.com/userData/board/file/fuzefejedejumun.pdfIn PDF document text
    • https://paulogomeslda.com/userfiles/file/47769288122.pdfIn PDF document text
    • https://wwa.bdbabymart.com/app/webroot/ckfinder/userfiles/files/5308205307.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/gotomixod.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_off00011578.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11578 18168 bytes
SHA-256: 76c817a323ff2077c47b465476fb0d4ffb70c394b722e2b7f95e1623822420d5
font_01_sfnt_off000144fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x144FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015d15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15D15 10756 bytes
SHA-256: 5cf98bf894a0a54b673dda71a52e9ab4d39ef06facc8ed522bc0646286e2017e