Malicious PDF — malware analysis report

Static analysis result for SHA-256 54a2ac51fc3d8902…

MALICIOUS

PDF

85.0 KB Created: 2021-08-20 01:15:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 42cdc02e6f77e02def297fed76dd7499 SHA-1: c060a3a32d55b5d187d95f4de5872e777c6f9db2 SHA-256: 54a2ac51fc3d8902eb815872b80599e28dea90e8db5830f87e035f563eae6fc5
96 Risk Score

Malware Insights

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

The ML classifier and PDF heuristics indicate this PDF is malicious. It functions as a link farm, with numerous embedded URLs pointing to other PDF files hosted on compromised websites. The primary goal appears to be SEO poisoning or distributing further malicious content through these indirect links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://volareinmongolfiera.it/userfiles/files/kizisaraseliri.pdf In PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160ad464006e43---27007807878.pdfIn PDF document text
    • http://cukrarnakolbaba.eu/obrazky/files/febevubenepu.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071c8d831c63---64093331337.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1610071fe86839---43409470171.pdfIn PDF document text
    • https://rubyyadav.com/nbloom/fckuploads/file/tiduwipotugaril.pdfIn PDF document text
    • http://centralgiving.com/media/userfiles/file/razimajup.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ce4792bb097---muvebemubilup.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607765f6e97df---zimuvexegamofawij.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/20215142018304715.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/33626391822.pdfIn PDF document text
    • http://stfrancisfrankford.com/clients/9/90/9051900d87e3fdd5bc97eff612ac54c4/File/repironiz.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/0k3qdcrksqj36hee3e8f6kpmn6/14991561016.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086ab7f70417---sutelawaba.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/e011a54b226bd1e22608f52627518978/lepoxiloju.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/6c5a8c9e3cd9633d16c898c780f7b33c/89986158356.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c11fb1eaa---boditiwab.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7cc2ea2289---7237046573.pdfIn PDF document text
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2568743a53---20960100548.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b986f336568---84962709494.pdfIn PDF document text
    • http://textingrights.com/userfiles/files/lisejitevori.pdfIn PDF document text
    • http://www.haztartasigepszakuzlet.hu/pics/file/45701788875.pdfIn PDF document text
    • https://fajanav.com/aym_image/files/63163519123.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/a7sjcmlbkftgv6382kbbmko2oq/56125091166.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=download+all+fusion+360+filesPDF 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_off0000e65d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE6F 17528 bytes
SHA-256: c767f26032a3e50e8feb6ce8af6dc3e9cc961993e1337b9079697ecd1c044514
font_02_sfnt_off00012c2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C2A 10796 bytes
SHA-256: 617d7deff535ee9cef9cb7d2b09947b52efd874c4fb0bb6e3309dc14e6e6a522