Malicious PDF — malware analysis report

Static analysis result for SHA-256 112c22a776b9c77f…

MALICIOUS

PDF

73.7 KB Created: 2021-06-13 11:05:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: d55bfbac9cb9dc414f500e283c024037 SHA-1: 8d76e17e96b87b3278f76a9a6e1edc76f565d593 SHA-256: 112c22a776b9c77fb139cee96b244e1aac4b953a602c0a4554cfc9ba2ce86d66
156 Risk Score

Malware Insights

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

The PDF contains numerous URLs embedded within its structure, many of which point to compromised WordPress sites. Heuristics indicate this is a link farm designed to exploit SEO keywords, likely to trick users into downloading further malicious content or engaging in phishing. The ClamAV detection and ML classifier strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://crysiq.ru/uplcv?utm_term=kcse+biology+essay+questions+and+answers+pdf PDF link annotation
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/knvg0j27bm33rj4clb989j7at9/56179191139.pdfIn PDF document text
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/31574ae40b01f9bc095ee432e2e361da/kotikinupopazobikino.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bec2c252ea4---luzovemobelexusinafaka.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c4f6721d792---nalifumefaginugizelutona.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4ee914f478---basawitulagoruwu.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/bb1baa2800ad9b5a096a0b86051f9b0e/7271990825.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1606ea4aacf7a8---ximurexafebipaxolud.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cdfde1b8a8---gubodexirive.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/82936a7fef4b15f2e545cc13b494d226/19145522184.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609f2b7403aa0---mufinasomasapov.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/jewuseguf.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16078bf8a6a20c---40536200922.pdfIn PDF document text
    • http://ofipapel.org//ckfinder/userfiles/files/81264184219.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160916a81e5a4f---71891347158.pdfIn PDF document text
    • http://allycatering.com/userfiles/79055594691.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160853bcb7c87b---pefalirepirokulibeni.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dea5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEA5 5752 bytes
SHA-256: ed8575f08b3cc91155b8946cd7971d40e61e2ec4740b38eb540871fab1344e52
font_01_sfnt_off0000f25f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF25F 11044 bytes
SHA-256: 66e0859b106a6993701909abb260e4e016c9a3762aeefc23875b35f9fa7e491e