Malicious PDF — malware analysis report

Static analysis result for SHA-256 7837ec9abcb11559…

MALICIOUS

PDF

73.5 KB Created: 2021-08-11 23:53:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 5f117c2af7fe41af73c0033b0fd4057b SHA-1: b341c69f10a3f395375d4ec5e19b2a54a0d9d99d SHA-256: 7837ec9abcb115596eca86b64cf7988326038c46c95873e07e832989fa80c4c2
96 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which appear to be compromised CMS uploads or hosted on disposable domains. This suggests the document is designed to act as a link farm, potentially for SEO manipulation or to distribute further malicious content. The ML classifier strongly indicated maliciousness, supporting the interpretation of these links as part of a malicious campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

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://ost-fogging.com/upload/files/42068175282.pdf In PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16111938ba8d97---13322484920.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/74346999904.pdfIn PDF document text
    • http://lucann.com/Upload/file/19623335755.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/c04fa84f38e887b52da2bda17d685a48/61328249445.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/71782975695.pdfIn PDF document text
    • https://englewoodgrassfarm.com/wp-content/plugins/super-forms/uploads/php/files/69f642a95c4c1269754da48e1bc106c3/zakokego.pdfIn PDF document text
    • http://herningbadintra.dk/app/webroot/upload/files/gegaselujanigo.pdfIn PDF document text
    • http://hasyo.net/files/file/97276134052.pdfIn PDF document text
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160a4bb98d1c03---nagesareve.pdfIn PDF document text
    • http://www.look4job.gr/images/_user_na/file/34381021782.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098ba17698ea---nasolesupimawefabitatet.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16085130650dbb---22850508619.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f8aac585cf---57124687222.pdfIn PDF document text
    • https://www.enterpriselighting.com/wp-content/plugins/super-forms/uploads/php/files/14b1cec5218ffea73afd5b2d9a5d5a03/pesiwedevu.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b2ffbcc5dd4---14665354372.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8a20773193---bexusira.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/87228976d1b83f5d26bab10ab1f06f0d/fonobezogomopitajedego.pdfIn PDF document text
    • http://arniestribu.com/campannas/file/vugofe.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/0b9c92216b967bdfee4c4dd05cdab145/62276793569.pdfIn PDF document text
    • http://asbazainville.org/userfiles/file/ronugugeminomufuwofokuzik.pdfIn PDF document text
    • https://sbsoftware.ro/admin/userfiles/file/lizuka.pdfIn PDF document text
    • http://alfadent-volg.ru/images_uploads/files/nidujukolofavodomasufaj.pdfIn PDF document text
    • https://jaiminsales.com/ckfinder/userfiles/files/resulogegapabosesari.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=teclado+netbook+acer+aspire+one+d255PDF 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_off0000b9a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d1bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1BC 10956 bytes
SHA-256: 30395a707e5fcea552f7c9087c291ee55e022524dff4a70a4565ea14c2ef0aaa
font_02_sfnt_off0000eb1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB1E 17548 bytes
SHA-256: b291ef20e583318a4a99f20b1aa172dd41763ab8a8cbc89d1347fe4e784a7ff3