Malicious PDF — malware analysis report

Static analysis result for SHA-256 803273a303300ce7…

MALICIOUS

PDF

86.5 KB Created: 2021-05-07 02:06:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: abd16199256660908baa0ec2fa2e98b5 SHA-1: 087e1d7af4fed01a161e9d549734f7c6e2985017 SHA-256: 803273a303300ce7210990774699b0fa3ad788d7448a106fb974887412012cc6
186 Risk Score

Malware Insights

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

This PDF file contains a large number of embedded links, many of which point to disposable domains, suggesting a link farm or phishing operation. The primary embedded URL, 'https://xezojetit.ru/strik?utm_term=countable+and+uncountable+nouns+exercises+pdf+intermediate', is presented as a resource for English exercises, likely a lure to direct users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 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://xezojetit.ru/strik?utm_term=countable+and+uncountable+nouns+exercises+pdf+intermediate PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4409123/normal_5fe9c8aebe095.pdfIn PDF document text
    • https://cdn.sqhk.co/gadowikuxe/igcidjh/51600898005.pdfIn PDF document text
    • https://cdn.sqhk.co/rexukewanej/cjcOry0/lebiwikomo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425230/normal_6013d0e6b4b8d.pdfIn PDF document text
    • https://cdn.sqhk.co/xivomojuf/ggjbnhf/making_a_balloon_arch_kit.pdfIn PDF document text
    • http://xazixovabifin.medianewsonline.com/axis_and_allies_1941_board_game_rules.pdfIn PDF document text
    • http://lufexaxoxak.mygamesonline.org/dijolufujujarulusupo.pdfIn PDF document text
    • https://cdn.sqhk.co/dutebevon/i33IjaC/sunulupaputuvupejofofox.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4489429/normal_600475b26a585.pdfIn PDF document text
    • https://cdn.sqhk.co/tegatiwuwax/LVm1ggK/f1_manager_2020_guide.pdfIn PDF document text
    • https://cdn.sqhk.co/kinanekoxo/iaZhahd/16282715135.pdfIn PDF document text
    • https://cdn.sqhk.co/weruvewo/chhhdhh/44295269387.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • https://14319df0-7947-4f0d-bbb3-eaa17d5eb23e.filesusr.com/ugd/c45f38_38ca68dc35a84342aec86e6c62ca8ba4.pdf?index=trueIn PDF document text
    • https://c78ffd2e-fc3d-4272-86ca-968d835fb7ad.filesusr.com/ugd/0f9ef0_b2765db87d244b92a0711884d89545df.pdf?index=trueIn PDF document text
    • https://ebba3e40-d49f-4cc8-b137-373bb1124918.filesusr.com/ugd/384ea4_9062339e8e8943ed9386e33559ea49aa.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/belapawerezuju/why_is_my_airpods_mic_not_working_on_zoom.pdfIn PDF document text
    • https://s3.amazonaws.com/popisiburewixuj/penny_stocks_list_2020_india.pdfIn PDF document text
    • https://s3.amazonaws.com/fovezewi/juego_gentilicios_provincias_de_espaa.pdfIn PDF document text
    • https://a1359116-1358-4cde-afc5-3600b4bb50db.filesusr.com/ugd/3b0c81_d134a01e2c8c4ef09608f58579316235.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
    • http://www.gnu.org/licenses/gpl.htmlIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fc29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC29 5416 bytes
SHA-256: 58cf5eec553ac41260ac082171bcd2096d3462a49f040954998cc337a3940899
font_01_sfnt_off00010e6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E6D 7716 bytes
SHA-256: 4ce3fc7d5837da7129642fdae4f3203ccceca7850a7016ad74d75932eb574f83
font_02_sfnt_off000123d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123D2 11320 bytes
SHA-256: 77afc48bb0022295b2fe0599e4fa88dd1628b60c66ab436f2f62a4b651241caf