Malicious PDF — malware analysis report

Static analysis result for SHA-256 d31cf55a59a7b6a2…

MALICIOUS

PDF

84.6 KB Created: 2021-09-17 20:21:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9e29e0a16c39e16c377dd0929f6caae9 SHA-1: b0d175347e43b6584b6526f537f65df6a2cd5c5b SHA-256: d31cf55a59a7b6a26974f12b1ca449fda444abb0497cd17c5c638058243625d2
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to other PDF files hosted on potentially compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The structure suggests a link farm designed to obscure the ultimate destination or to host a collection of malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://akproauto.com/nbloom/fckuploads/file/vudozixose.pdf In PDF document text
    • http://dydlhx.com/upfiles/file///35965578745.pdfIn PDF document text
    • http://tgroupsrl.com/userfiles/files/pibumegavitat.pdfIn PDF document text
    • https://mmgrowersg.com/ckfinder/userfiles/files/63305768735.pdfIn PDF document text
    • http://cavusofis.com/images_upload/files/fuvapate.pdfIn PDF document text
    • http://almar-bus.pl/userfiles/file/xadopusafizilo.pdfIn PDF document text
    • http://escritacontabilidade.net/fotos/news/file/45318082493.pdfIn PDF document text
    • http://cbcom.fr/ressource/site-image/files/24328965134.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/c9fc4b9216d0646151403d9ba936267f/67877757319.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/86985302568.pdfIn PDF document text
    • http://ramenhajimetustin.com/uploads/files/xejivo.pdfIn PDF document text
    • http://astprom.ru/sites/default/files/file/49307657156.pdfIn PDF document text
    • http://www.tivafa.hu/upload/file/72081598292.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/64199338911.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/80d2747e91f8f5e2df0709da9a7274b6/makin.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/b1305ad7364c9ec672e15f9928cb604f/28379179443.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/nv9qv85o6kce2cbh599jahoh3b/23177776770.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/161404b1c23ef3---35767378504.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee1ce38f97---disejesel.pdfIn PDF document text
    • http://veterinariacasettamattei.it/userfiles/files/kinorereralugeresi.pdfIn PDF document text
    • https://cortopolis.ar/userfiles/file/tiwoxopetu.pdfIn PDF document text
    • http://cieplej.pl/imgturysta/file/simasubekurem.pdfIn PDF document text
    • http://kantipursecurity.com/userfiles/file/pulukadexuxaxumamofiferoz.pdfIn PDF document text
    • http://fsgzb.com/upfolder/e/files/20210909122918.pdfIn PDF document text
    • https://podiummagazinenews.com/ckfinder/userfiles/files/62626869112.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=bad+things+that+start+with+aPDF 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_off0000e6c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000feda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEDA 10368 bytes
SHA-256: 2f74a02c89fbce80a91d6abc664554f119dacceba9cd7d9f84d5dc9c2f6fd677
font_02_sfnt_off0001160d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1160D 18168 bytes
SHA-256: e9c5c7d690b6774a6a753757868c80451610697fe7f60a5514de5aabcf14defb