Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5d697b18831f7d9…

MALICIOUS

PDF

83.4 KB Created: 2021-09-13 14:27:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e97b65d61099186afebf9ec4e0782343 SHA-1: 9f6bd1a0f275c260f9eed89ea28cc3b7104a4205 SHA-256: c5d697b18831f7d9d4b44c384026693db6f01467d9226673a81945d5a682cb4d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs that function as a link farm, directing users to various domains. Several heuristics indicate these links are hosted on compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The ClamAV detection and ML classifier further support the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://jjinline.org/file_upload/file/buzubedomajesavid.pdf In PDF document text
    • http://www.psoealora.es/ckfinder/userfiles/files/butibalakidilolebesazewaj.pdfIn PDF document text
    • http://goksirlambinowice.pl/img/upload/files/xuxebujudanu.pdfIn PDF document text
    • http://www.salpasafarit.fi/tiedostot/files/nawosinazolejujejap.pdfIn PDF document text
    • http://efuturesthai.com/uploads/files/relonufox.pdfIn PDF document text
    • http://studioscoponi.eu/userfiles/files/50509299985.pdfIn PDF document text
    • https://sanghvicranes.com/staging/media/86840428027.pdfIn PDF document text
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613b36ef10f25---busojexeserol.pdfIn PDF document text
    • https://apartmani-mestrovic-krk.hr/files/53831969792.pdfIn PDF document text
    • http://www.szphotar.com/admin/img/files/43864874498.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161320c48b497f---fusutudiwomenobefuxogatu.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613267da8b1f1---jazoxowonukiwupodi.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/nolego.pdfIn PDF document text
    • http://xinyuemu.net/assets/202109/files/20210913043525455457.pdfIn PDF document text
    • http://horvathortho.hu/tmp/28230838164.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/kafezakosuvibonividukojaz.pdfIn PDF document text
    • https://gizaviation.com/uploads/files/begov.pdfIn PDF document text
    • https://imaggu.com/ci/userfiles/files/safiboluwud.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/tasopuxazisoxano.pdfIn PDF document text
    • http://www.oomedia.com.tw/ckfinder/userfiles/files/9605185071.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133a9121084b---wuwaviwazowunogelaxenof.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=free+fire+mod+menu+appPDF 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_off0000e153.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE153 10424 bytes
SHA-256: 4d206886fa7c93fe650f56bcd41769674adfedeef3a3a796649d1afc6de52941
font_01_sfnt_off0000f8d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000110e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110E4 18184 bytes
SHA-256: c5d9212f6ac01a3aeee02b2b75dc315be4d0931bfdb46dc3cc7e76c1df0395bd