Malicious PDF — malware analysis report

Static analysis result for SHA-256 831ba23bf8221a7e…

MALICIOUS

PDF

67.6 KB Created: 2021-04-14 06:49:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 78f18795ef5ba184005e48c9f3e4dabc SHA-1: 7307a2970debaa62e34f5816547ba47975e3603e SHA-256: 831ba23bf8221a7e77704b93e45aa5c0709a2266eecdd417cc03180453999d78
126 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jumiwimov.ru/strik?utm_term=hp+deskjet+d4160+color+ink PDF link annotation
    • http://help-bluebadgecenter.com/writing_task_1_bar_graph_for_practice8hfpb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4409123/normal_5fc601b4e70c8.pdfIn PDF document text
    • http://hamsterbig.com/download_fonts_for_word_2016jofw6.pdfIn PDF document text
    • http://italia-doc.space/80878163406xlb0a.pdfIn PDF document text
    • http://beautysss.site/rise_of_the_runelords_anniversary_edition_players_guidemv5he.pdfIn PDF document text
    • http://internet-babki.ru/how_to_connect_onn_tv_to_comcast_remote6asvu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391314/normal_5fdc40f06f806.pdfIn PDF document text
    • http://svoylend.xyz/king_lear_movie_summaryl3so2.pdfIn PDF document text
    • http://cherrypimp.online/lixofatagisejocnqe0.pdfIn PDF document text
    • http://kkkirrreeee.space/xegejawund03.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://70fbc5f3-53e4-4072-9ff7-a5862d19847b.filesusr.com/ugd/bb3bf9_e0411069221f4438bf1f45c7de0d4811.pdf?index=trueIn PDF document text
    • https://5ce19dfa-329f-495d-88d1-e1e7834d9072.filesusr.com/ugd/d902bb_47148eecf5334bbb9a5be6448b3e5866.pdf?index=trueIn PDF document text
    • https://83bd47e3-138d-48d8-8d00-514fe13b91b0.filesusr.com/ugd/c87a2f_d8a80eb90ea641bab485281affdc13a6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kalanejaxutilif/88418184208.pdfIn PDF document text
    • https://s3.amazonaws.com/bomupi/cover_letter_template_nz_careers.pdfIn PDF document text
    • https://s3.amazonaws.com/nelizenejakarug/how_does_girl_interrupted_portray_mental_illness.pdfIn PDF document text
    • https://s3.amazonaws.com/pevarijidasalop/texos.pdfIn PDF document text
    • https://c2c662fa-00ac-4c69-bf5d-04da7d6c99e2.filesusr.com/ugd/9b33c5_c0eb3d26b6ca4e1da9b132313aa576ad.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_off0000cb69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB69 5396 bytes
SHA-256: f629faef8b95cdb8ab08bf80096c0a34c70f56f43d0c334be0abdf60348b6dae
font_01_sfnt_off0000dde9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDE9 10400 bytes
SHA-256: e8bc90ecfee775dab1677579cdeb16642ba716b07c537bda464eb5a66d48ef51