Malicious PDF — malware analysis report

Static analysis result for SHA-256 98173361c555b083…

MALICIOUS

PDF

76.8 KB Created: 2021-07-02 04:49:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: f68720f60f9eee4968baa7f8a388abb9 SHA-1: f3698c2534400f9d98b7149c156c24ed8fd3d0af SHA-256: 98173361c555b0839a28874f91b6e2429f46e225fb4e42af11db0606a772c737
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a phishing or malware distribution campaign. The presence of multiple external URIs and link farms indicates an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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=product+key+professional+plus+2016 PDF link annotation
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/6fe9u4hibj22ou3hg4qvbptjsf/fuborozis.pdfIn PDF document text
    • http://whsclass1968.com/clients/f/f8/f849445bb2fb8f42e7c863050dc1ba38/File/sosupu.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/3f3a1cb130e596a1691a84b9ad669279/dopijevugigowa.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/k2gu1sut3tucpsh5q15mb472ok/tajugixapipoketa.pdfIn PDF document text
    • http://bonfiremadigan.com/uploads/fckeditor/file/vakusoluximoxuxutututuju.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607e10f1c62d0---66134113709.pdfIn PDF document text
    • https://www.varisistanbul.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072ff38b2716---garutaza.pdfIn PDF document text
    • https://alternativecarrepair.com/userfiles/file/50821276540.pdfIn PDF document text
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/c251l8a9iqs4p72imlh0mjgrog/feforazetikibiw.pdfIn PDF document text
    • http://amandamaitland.com/images/file/zasuzeravi.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/160aaff8ce4806---97371534075.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/14da1cfedc9dab5c1f1c324d4c477a3f/sejexewomazilalezakoj.pdfIn PDF document text
    • https://yuss.it/file/76242189030.pdfIn PDF document text
    • https://askopenko.com/wp-content/plugins/super-forms/uploads/php/files/34fa706f1811db4cd7b98016451d0312/gejuturulatidu.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/84e258ce84d2b4827867e1c466b415ad/41368259694.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8718dc975---77980245789.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160926cdd54b9b---5653404576.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-6/file/pabadoxakovonulalulok.pdfIn PDF document text
    • http://magendans.com/imagefiles/file/vuguketatuzugos.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc538e02f1---66617949948.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/96848953930.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b761bf82660---12240228181.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bbe39dd1328---nepadekizuvepivesobarud.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/0d8d4a49894f0048d9d69c273588d483/fukifetolivoxiz.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/bexobarigopudipomubotoz.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfef0b6d928---49376113417.pdfIn PDF document text
    • http://whatifitspossible.com/ckfinder/userfiles/files/65344730601.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_off0000c4ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD16 11380 bytes
SHA-256: 05ee27d4aa67db9e05c805e16bcc8377b955486684d6a364f1971ab66cfd7cbb
font_02_sfnt_off0000f82c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF82C 17364 bytes
SHA-256: 565be98d0d087fb78a5c35c4ce59ae8de6c330997707a8e6b32fa0b3bde4c852