Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b75ecd1fe53f562…

MALICIOUS

PDF

88.3 KB Created: 2021-06-28 10:15:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: cdf73c930dce1efea8ccedc203ee3e83 SHA-1: 1a5563030985f6930372f667dd4dcba6c8cdd7e6 SHA-256: 1b75ecd1fe53f56257d3d17a4e5243489f643a88d21060455d7e88e83563068d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites utilizing the Formcraft plugin for file uploads. This suggests the document is part of a link farm, likely intended for SEO poisoning or to redirect users to malicious destinations. No scripts were extracted, and the document body was unreadable, limiting further analysis of specific user-facing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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.bistro-e.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc2a78d9ee---zojuvixunetoj.pdf In PDF document text
    • https://contabil-fiscal.ro/mm/file/81870850030.pdfIn PDF document text
    • https://rieker-consulting.eu/files/file/kalijexo.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cc1fff3fc8e---25268799865.pdfIn PDF document text
    • http://internationalnetworksolutions.net/files/In PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5f58db3318---56277534704.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1606d2441b453f---fevazinelitudizakaxekajev.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609fdf00e5af5---6326698583.pdfIn PDF document text
    • http://mosjob.ru/images/file/30375253317.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c1654e406eb---22745982734.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160730c22c1ff5---90857900051.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/70f5fe0ce5c4c7cc0d62aef5fddb6808/1492135173.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/kmbu758qoi5p7h8megjkcflgad/60418792052.pdfIn PDF document text
    • http://meechoktoolmart.com/user_img/files/lozikuxawibuzedupovu.pdfIn PDF document text
    • https://geneolock.com/locktactyuma/userfiles/file/83361290408.pdfIn PDF document text
    • https://grup-insaat.com/userfiles/file/pomixut.pdfIn PDF document text
    • https://www.sudburyhighspeedinternet.ca/wp-content/plugins/super-forms/uploads/php/files/4b4a6380a699a22b39a74f44f1c66ed7/7015253432.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/453c3f8719ad5c088f01fe5457aa8bda/8246554994.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/8e692d129e4484c3ff93fa29f2a5ec33/35785400124.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ba7ecbb53b1---baximevix.pdfIn PDF document text
    • http://qzgj.cn/upload/file/51583717401.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4fef853500---silizenirajaw.pdfIn PDF document text
    • http://iaestedresden.de/userfiles/file/72106840284.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=gk+question+2021PDF 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_off0000f5dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010dee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DEE 17644 bytes
SHA-256: 5cc89aaf2682d272c66bdecb758d575dd834049dd86d2fa6be60baf64968b010
font_02_sfnt_off00013c12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C12 10464 bytes
SHA-256: 146dafb1ba8ecb489188fc827a426b154e9dd2c641ab788b4d0e0f55996e01aa