Malicious PDF — malware analysis report

Static analysis result for SHA-256 a31e2d95f7e910b9…

MALICIOUS

PDF

81.7 KB Created: 2021-09-07 04:00:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 051521c192737e4202bb74517f58e15c SHA-1: 557dfd7bc84ec422530dad3b3b7c0a05b8a567ba SHA-256: a31e2d95f7e910b926d7b428d2f2f1310d00b432aa9412b70b9bdf82abf0262c
96 Risk Score

Malware Insights

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

The PDF contains numerous external URIs pointing to various websites, many of which appear to be hosted on disposable domains or compromised CMS upload directories. The ML classifier strongly indicates maliciousness, and the structure suggests a link farm designed to redirect users, likely for malicious purposes such as phishing or malware distribution. No scripts were extracted, but the presence of multiple suspicious URLs is a high-priority indicator.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://chcial.ru/uplcv?utm_term=naturetti+capsula+bula+pdf PDF link annotation
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/16082fec49ccab---10140053229.pdfIn PDF document text
    • http://stlnsk.ru/uploads/file/dumojuzed.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/857376b463b1a369bf484b8c24a4d4ce/21233946621.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/dewawi.pdfIn PDF document text
    • https://intervalhousehamilton.org/ckfinder/userfiles/files/3390403591.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/gralr6pbdrlb0fdk50gvkluqh6/sonenaliv.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16125f825c14e5---donukal.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/5b5e1ec24e339c2e474f0313413f169b/54078563999.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/323c522e44c81f2af178f7e383bb0f39/70048675283.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/ca78d5a21e351a9bd06bd045f10697e0/nejug.pdfIn PDF document text
    • http://bannails.com/fckeditor_userfiles/file/kulurivajis.pdfIn PDF document text
    • http://hyunbulsa.org/~ewedd2/userfiles/file/fexojega.pdfIn PDF document text
    • http://euro-ex.net/images/blog//file/komipiremafodewiru.pdfIn PDF document text
    • https://globalybm.com/ckfinder/userfiles/files/1626344920.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/ddd0388e86a117f60d27631b40a8842d/11930858489.pdfIn PDF document text
    • https://777mto.com/contents/files/xezixutewupujewavetojogu.pdfIn PDF document text
    • http://smn1970.com/clients/d/d4/d44d2684521ac238e4bdef02d06179b0/File/68500291390.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6bf396e979---29513326991.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6e71f8fe93---2837777817.pdfIn PDF document text
    • http://opakowania-loga.pl/zdjecia/fotki/file/dolapezivetoxo.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b52868e2af7---23801153323.pdfIn PDF document text
    • http://doanekeyes.com/userfiles/docs/94463429434.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_off0000d448.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD448 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5F 10608 bytes
SHA-256: 034a9d505fc0f71d3849dc4228d35f9416eb55b7d2301275917ebd6de195f696
font_02_sfnt_off0001047c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1047C 19832 bytes
SHA-256: 92a651325830e44dd90b3f1cfa6976fa6dc6073207b40b8cd41cda360f088d67