Malicious PDF — malware analysis report

Static analysis result for SHA-256 77106bf4a5aa055a…

MALICIOUS

PDF

85.8 KB Created: 2021-06-11 03:06:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: f216a53577c0c5d17edd0d130b064802 SHA-1: 9c360a236ad1aab83adf442470be220134813900 SHA-256: 77106bf4a5aa055a97f8e870c8ad44b42aee3910ac9c658080096c060111b4ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://oniceh.ru/uplcv?utm_term=english+conversation+at+restaurant+pdf PDF link annotation
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081d01b96e8e---jokeruxigufalunulavo.pdfIn PDF document text
    • http://learningkey.org/userfiles/laxerikovum.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160b0917a46bce---suninazomijesarasit.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b6813d98cac---11438017224.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/e54b51916ead1afc4e5ff17fd37ea8e5/lokeroxujiserujirotuko.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7b08d2113---vudop.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609838367eac6---gikumolup.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/91c2e6d1adfa9a39557f5d796915c7a9/65606091322.pdfIn PDF document text
    • http://aite-materials.com/upfiles/file/devub.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/864ccdfefcf31c1489897816a1105ba0/lepidekuroleso.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081352cca57d---govek.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e0593ab390---68369707941.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b3f12623ef8---rizitataxedevew.pdfIn PDF document text
    • https://www.ideaklinikankara.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d14a72651b---85766992926.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00011be1.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x11BE1 25376 bytes
SHA-256: 18058b9611bc4b7b99440376855020053077beaeb7f9c5075acb45074511d33a
font_00_sfnt_off0000e4bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4BF 5432 bytes
SHA-256: 1b235d3900445fb4d6e1a747903d79e449dac0e654e51945fee6d7e261375474
font_01_sfnt_off0000f74a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF74A 10592 bytes
SHA-256: 2e59ca80492d2f2d241a7efaf6c6d47afb1f7137985491a68df68b99776a8f5d