Malicious PDF — malware analysis report

Static analysis result for SHA-256 4157c0bcdadd00ed…

MALICIOUS

PDF

86.7 KB Created: 2021-08-25 23:02:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: e9c1876c217b4bf1643cf3730f7304f6 SHA-1: 7bcf486f3d5148db0c01e0e229c38a117195a81e SHA-256: 4157c0bcdadd00ed0426c82e34147f6a132b424b088cbd87297c12ccff0df1f7
96 Risk Score

Malware Insights

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

The PDF document contains a link farm with numerous URLs pointing to compromised CMS upload directories. These links are likely intended to lure users into downloading further malicious content or visiting phishing pages. The ML classifier strongly indicated maliciousness, supporting the assessment of a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • 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://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/gb7rpovliindltmg6otu9lbl86/zizozajo.pdf In PDF document text
    • https://elmawadah.com/userfiles/file/jasunupuduvor.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/24164509795.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160ec4ba069992---luwozimonuwadat.pdfIn PDF document text
    • http://verlauf-ekb.ru/admin/ckfinder/userfiles/files/65094372845.pdfIn PDF document text
    • http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16086d5d6ecf02---xojeku.pdfIn PDF document text
    • http://almar-bus.pl/userfiles/file/86237003341.pdfIn PDF document text
    • http://architettosbaffo.com/userfiles/files/40068090648.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/f1bb8ac4b3924c8c3c112afed228287c/61565411720.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/jofopa.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/sezipon.pdfIn PDF document text
    • http://sdds.be/userfiles/file/98369647284.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16095add8aaa64---keruza.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160bf588b3076f---xosoxiso.pdfIn PDF document text
    • https://seataclighting.com/wp-content/plugins/super-forms/uploads/php/files/4e084c143b951d4ec50c4c11092f0cd2/50069999476.pdfIn PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/bdfce405f3a9aa0dea62c9ae9de7001c/ronolijalubatokosabitowek.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c7ba9bb21a0---xodazonisiwuxexejoliz.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c44370a29ad---63169577259.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160f131c502ca7---tavipemoz.pdfIn PDF document text
    • https://vildmarksjagt.dk/userfiles/file/33744731821.pdfIn PDF document text
    • http://happyland-nsk.net/ckfinder/userfiles/files/juxidetafesesagozobopoded.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1609b77acccbc9---98017226117.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=spinach+for+rabbitsPDF 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_off0000f113.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF113 10612 bytes
SHA-256: ae6f6bb27e02d64ea2b228252e9bf82031813388971535069782fb71595a6ae4
font_01_sfnt_off00010901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10901 17108 bytes
SHA-256: b7e2c2c37eb60d6d970702876d4d807972108bc537fcc417ecaf1c8bf9fabf39
font_02_sfnt_off00013563.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13563 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1