Malicious PDF — malware analysis report

Static analysis result for SHA-256 df8a1ef304e08568…

MALICIOUS

PDF

74.9 KB Created: 2021-10-17 09:14:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d099ba5bbd07062cd469723aab4e1baa SHA-1: 6be93dbb5535e4c63b9167e64d7b55ee2b9566f3 SHA-256: df8a1ef304e0856821032638fb8931defa3c18aa9baa363a1c7f7f59baf61e95
124 Risk Score

Malware Insights

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

The PDF file was detected as a phishing trojan by ClamAV. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to external sites. Several of these URLs are hosted on compromised CMS uploads or disposable domains, indicating a likely attempt to lure users to malicious content or phishing pages. The authoring application 'wkhtmltopdf' suggests it may have been generated programmatically for this purpose.

Machine Learning

  • Nyx PDF Classifier clean score 0.2255

Heuristics 5

  • 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
  • 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://washlounge.in/ckfinder/userfiles/files/fipewubemetezekenomuzome.pdf In PDF document text
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/sevetuguwutixebadiga.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132d73ad046e---8879314415.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/66338898339.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/2021919717197298.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/pisowipewowudafire.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/161328119e1442---40595857174.pdfIn PDF document text
    • http://angelescare.com/userfiles/file/derivamupuliraxexojo.pdfIn PDF document text
    • http://timandlor.com/userfiles/file/15918432087.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/71702005995.pdfIn PDF document text
    • http://c-six.it/userfiles/files/gakenovaxipigatewofidob.pdfIn PDF document text
    • http://studioesflores.pl/obrazy/file/dusozulizateraxel.pdfIn PDF document text
    • https://cissud.com/uploads/ck_editor/files/betujawawixasozajewun.pdfIn PDF document text
    • https://thucphamtruongxanh.com/Upload/files/49207207871.pdfIn PDF document text
    • http://vejwun.cz/images/minipidexapirogovejokesej.pdfIn PDF document text
    • https://stephan-kratt.de/data/reiterhof/userfiles/file/guwipugigowidulojus.pdfIn PDF document text
    • https://eghamatyab.com/basefile/bainbookcom/files/36282557008.pdfIn PDF document text
    • https://astefin.ro/ckfinder/userfiles/files/69266101499.pdfIn PDF document text
    • http://olympusflights.com/files/files/72512379766.pdfIn PDF document text
    • http://ciaooo.ru/uploades/userfiles/file/kikamewuletazuziwekivixus.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/16148b52e2b12e---29054097306.pdfIn PDF document text
    • http://dichvuhangngay.vn/uploads/image/files/42672040912.pdfIn PDF document text
    • http://www.novosib-sport.ru/ckfinder/userfiles/files/96957764166.pdfIn PDF document text
    • http://tumakuruvoice.com/tumkurvoice/ckeditor/ckfinder/userfiles/files/ruzawejanekalet.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1616b0fc967290---bunisexum.pdfIn PDF document text
    • http://blackhorsesc.pl/userfiles/file/48994100322.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/u-9XGpgKpwY/uplcv?utm_term=sturdevant%27s+art+and+science+of+operative+dentistry+6th+edition+pdfPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d86a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD86A 19016 bytes
SHA-256: 8977c3e7d71b1528e9708a6e859de596a41445b213cc3fd8cdf747b77cb03308
font_01_sfnt_off000108c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1