Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c22f5f1219d6f78…

MALICIOUS

PDF

74.2 KB Created: 2021-05-08 09:33:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: ce10f88c920408ed607d6c9e477a72dc SHA-1: 530a635a3b585a8c7643f29ee577149ce3e8e7dd SHA-256: 4c22f5f1219d6f788f91bb5c160246f5a7a1a4c72e233ccc3fd779fe02fcb329
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, identified as a link farm, with one prominent URL suggesting a lure related to 'United healthcare prior auth form medication'. The ML classifier strongly indicates maliciousness. While no scripts were explicitly extracted, the PDF structure and extensive external linking are indicative of a phishing or SEO spam campaign designed to redirect users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://kuzutuzo.ru/strik?utm_term=united+healthcare+prior+auth+form+medication PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4404969/normal_605a5bac4d149.pdfIn PDF document text
    • https://cdn.sqhk.co/tenalewi/aihifgh/pioneer_dj_player_online.pdfIn PDF document text
    • https://cdn.sqhk.co/fofodafexadu/bjfhbgg/sudoku_6x6_easy.pdfIn PDF document text
    • http://tajumizigareni.iblogger.org/auto_clicker_no_chromebook.pdfIn PDF document text
    • https://cdn.sqhk.co/fofateze/kiijaTM/nick_jonas_kingdom_character.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4371272/normal_5ff13e952bcb6.pdfIn PDF document text
    • http://wujejejifi.mygamesonline.org/49299159976.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4456999/normal_60442ecf4d144.pdfIn PDF document text
    • https://cdn.sqhk.co/businaxidare/QVShehc/exonerated_definition_example.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4389603/normal_5ff5a6cc4fecf.pdfIn PDF document text
    • https://cdn.sqhk.co/nokotadi/iegihbv/friend_finder_iphone_7.pdfIn PDF document text
    • http://wepijafiguwenan.mywebcommunity.org/dfinition_de_l_orthophonie.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486051/normal_5ffa3dcfda7e4.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://78ff948a-0765-49f5-a22c-0fbe0eba7848.filesusr.com/ugd/888d0b_d55cba077d7141ac867c8a1888a8deeb.pdf?index=trueIn PDF document text
    • https://5a995288-ce6f-4ae3-a3e6-14272d8003db.filesusr.com/ugd/7be1cd_7db5667b0a5a459db38656d950a69832.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/paxunu/pathfinder_inquisitor_archer_guide.pdfIn PDF document text
    • http://pojuxesut.epizy.com/ap_grama_sachivalayam_books_free.pdfIn PDF document text
    • https://s3.amazonaws.com/tobobowu/majawozofizawu.pdfIn PDF document text
    • https://s3.amazonaws.com/nojemi/sat_2020_scores.pdfIn PDF document text
    • https://e082cb0d-9c22-4a21-acb7-e2c6127a51d3.filesusr.com/ugd/ff0c06_03325fdec80449b799d95387a24a8caf.pdf?index=trueIn PDF document text
    • http://fevusavumerow.rf.gd/74755451238.pdfIn PDF document text
    • https://s3.amazonaws.com/nitatotol/bullous_form_of_lichen_planus.pdfIn PDF document text
    • https://16fd3b15-5541-4454-9538-28daacbf497e.filesusr.com/ugd/e32576_7a2dcea73f3b4f49855b43cfc299afaf.pdf?index=trueIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e38d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE38D 5208 bytes
SHA-256: 6ffaad21c034966c7fde4dc2442daf69543bbb16bf143b3b5003fd901ad3dd06
font_01_sfnt_off0000f51d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF51D 11116 bytes
SHA-256: 64890fe3252dabab4e312ea1d7fe4177cb67dd97e3c83f1f9cabb73cb8e6e544