Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4a423e943a74438…

MALICIOUS

PDF

149.8 KB Created: 2021-09-04 14:26:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 71806405a631608c3a471dc9a709d987 SHA-1: 2305234abe4af25096fb246c2c08b2adc5dcd884 SHA-256: d4a423e943a7443844e876d4529c97a18372cbd90afcfd604673befa3271fa9a
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to compromised websites or disposable hosting. These links appear to be part of a link farm, likely intended to manipulate search engine results or redirect users to malicious content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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=manual+tv+philips+led+40+ambilight PDF link annotation
    • http://uniradioweb.info/userfiles/files/59289944245.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160716ed97e5f2---81921627894.pdfIn PDF document text
    • http://ranaghatpchsschool.org/userfiles/file/86873651726.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/ofshm0ngm6f4bshp1sahg0lg7o/telezitonolasuxeni.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/76678984205.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/56762d46bff73e76154ba8e2af5239cc/60154232186.pdfIn PDF document text
    • http://theettiaresmontreal.com/clients/f/f0/f03dfc1790708d0b03c48e9879ef2ea6/File/82244357075.pdfIn PDF document text
    • http://yourhealthyanswer.com/ckfinder/userfiles/files/20763747954.pdfIn PDF document text
    • http://ski-experience-japan.com/images/blog/file/57218695053.pdfIn PDF document text
    • http://onlytech-tunisie.com/userfiles/file/75147106828.pdfIn PDF document text
    • http://zionhillfirstbaptistchurch.com/clients/73368/File/65611045956.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/44b2c8cc554308693ef658fb2899fa1f/5437772292.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/suzaturawu.pdfIn PDF document text
    • http://tantos.jp/js/upload/files/43009646661.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/51a25a55f2daad2b6a3534768e934d8e/vupumipikijovewu.pdfIn PDF document text
    • https://pestresolution.pt/site/upload/file/mizesukedagibapidiji.pdfIn PDF document text
    • http://dc-3ed4d7413bdb.prshots.de/uploads/userfiles/1629712330/files/fesepevipu.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b291a4af4a4---vibiteze.pdfIn PDF document text
    • http://kirsanov-maslo.ru/uploads/27350106832.pdfIn PDF document text
    • http://webinside.pl/userfiles/file/godobufegajikurak.pdfIn PDF document text
    • https://www.nexidia.it/wp-content/plugins/super-forms/uploads/php/files/ebc7613ed3f20d7802e5061c20c97c08/terujezatom.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_off0001df70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DF70 22000 bytes
SHA-256: 82d51297c4568440163e9cf1946fb8f2df8c2cde814bf5d55c93f5e9a591bc83
font_01_sfnt_off00021837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x21837 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0002304e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2304E 11120 bytes
SHA-256: 63b1154cdca5f7c350d1f4f9786c526e80e4fb403b8654ea7b765e2b75a2ae08