Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc7165d0f22bf857…

MALICIOUS

PDF

83.6 KB Created: 2021-09-24 11:50:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0a112fd56bf9dd7b72c40913fbac1d50 SHA-1: e205d2f022e16677512c0001aa795a4a3b19566c SHA-256: fc7165d0f22bf857db3ed7adbbf31311787c059e4b220386d39f73a2da465502
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is a tactic for SEO manipulation or to host malicious content. The presence of multiple external URIs and the overall structure point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://cructi.ru/uplcv?utm_term=moba+mugen+ml PDF link annotation
    • http://silver1979.com/upload/file/basit.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/fq1mtpl0nhb8ihi9koveev1ps6/29359304855.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149c89b74886---vegezi.pdfIn PDF document text
    • https://gulfb2b.com/userfiles/file/12642666155.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a5417f8a5---51925549614.pdfIn PDF document text
    • http://engineersclasses4competition.com/files/others/josakajuwexulozivorezoki.pdfIn PDF document text
    • https://munis-roquesalbes.cat/demo/vilalba/imatges/file/6287509435.pdfIn PDF document text
    • http://kup-vino.cz/web/ckfinder/userfiles/files/573302605.pdfIn PDF document text
    • https://optimumquestsolutions.com/ckfinder/userfiles/files/7593881635.pdfIn PDF document text
    • https://satuldelut.ro/ckfinder/userfiles/files/xobil.pdfIn PDF document text
    • https://dennismaloney.ca/upload/editor/file/vutokoz.pdfIn PDF document text
    • http://phuvuongcorp.com/luutru/files/gogimedo.pdfIn PDF document text
    • https://blueparadise.pl/userfiles/file/67737062438.pdfIn PDF document text
    • http://cross-winds.in/upload/contents/images/images/kibukekojobokepunuxud.pdfIn PDF document text
    • http://fandimnarodaku.cz/upload/file/4763515216.pdfIn PDF document text
    • http://urbanposthotel.com/admin/ckfinder/userfiles/files/konugeb.pdfIn PDF document text
    • http://masaze-bohunice.cz/images/texts/file/bugatanebene.pdfIn PDF document text
    • http://candybeauty.vn/upload/files/18187979062.pdfIn PDF document text
    • http://runwellconsulting.eu/file/file/kuvuzopumorokor.pdfIn PDF document text
    • https://bbpartner.cz/userfiles/file/10191610216.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/kejiru.pdfIn PDF document text
    • http://tatagz.com/uploadfile/files/nejiwatimukiget.pdfIn PDF document text
    • http://elencostruzioni.it/userfiles/files/bakosulekisexozin.pdfIn PDF document text
    • https://samajsutra.com/userfiles/files/54116282489.pdfIn PDF document text
    • https://expomediainc.com/upload/file/89052854136.pdfIn PDF document text
    • https://chilegastronomia.cl/uploads/userfiles/files/gogup.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/d54896d5b89c82befb71f2989060436b/fuxawukep.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_off0000e32b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE32B 17836 bytes
SHA-256: 839cc63dddc5d579082e0568711a58f1a4a6a4b80978240cbf7c4bc9933deb78
font_01_sfnt_off000111a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000129b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129B9 10228 bytes
SHA-256: ab3728c36e8d2334aa50393f1e1c5ccb35d090afe7c9db35bddc3d0e302090ad