Malicious PDF — malware analysis report

Static analysis result for SHA-256 838dd0442dd56d48…

MALICIOUS

PDF

83.6 KB Created: 2021-07-16 15:20:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1b6c3e827588ef818a4225ee3979d895 SHA-1: 568146615289e7086b70616819238e67856b33d6 SHA-256: 838dd0442dd56d48af34af463d67dea72f6eb016de4e3218098433e6c47ece21
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier strongly indicates maliciousness. The primary purpose appears to be directing users to external resources, potentially for SEO spam or to host further malicious content, rather than executing code directly from the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/d9e7171900a242c180d0e6048f16e1c1/wurabemaf.pdf In PDF document text
    • http://chemicalengineers.ie/images/vakodaroz.pdfIn PDF document text
    • https://gangnampools.com/contents//files/88949097100.pdfIn PDF document text
    • http://webbuilders.com/files/file/ralikesowaminewugoj.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/fea3ac4fa5f665ed75e3abf57d182401/wegipapatasoluv.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6e06c55dca---76119197323.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b22bcaa85ab---44392120208.pdfIn PDF document text
    • http://thaisomboonautopart.com/userfiles/files/kolesakef.pdfIn PDF document text
    • https://vongtaytramhuong.vn/upload/files/49241217840.pdfIn PDF document text
    • http://duoctruongxuan.vn/userfiles/image/file/89683004414.pdfIn PDF document text
    • https://apotekatia.ba/fajlovi/rinejifadon.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/wadexe.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160db2dde466c7---kasex.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/99e122f3769b378a531dc47f22d9142f/61688933200.pdfIn PDF document text
    • http://fincasotilloviejo.es/files/sotillo/_repo/file/radalofosokebosewija.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5a8249dfc---zuxujo.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/ffe7f6ff3e2cf4717f5abdf9e77e78c3/pitiwimidolofujipa.pdfIn PDF document text
    • https://alrashed-alsaleh.com/userfiles/files/44836615677.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16079aa7f4388d---filugobugejozibugafesopa.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f85faa39d2---54420608418.pdfIn PDF document text
    • http://ordinate-ltd.com/file_media/file_image/file/zodobuguwaxaxuloditixol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=treatment+for+bruised+ribsPDF 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_off0000e437.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE437 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC4E 10672 bytes
SHA-256: 1e49cbbc85cffd9604baea8d32d2a8595f816f63a8a3907ff2ae15b097d5f511
font_02_sfnt_off000114b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114B6 17160 bytes
SHA-256: 355a135dbbc6407f097277ced2f0881cc447ad6373d4f38f3b95c480aae6adfa