Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a1d04e3e7b88921…

MALICIOUS

PDF

83.6 KB Created: 2021-09-13 19:33:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 97dd36cebac7e734b53db48211be86f5 SHA-1: 0f5d803ac9730c72297e8cdeb82ab5f0179f27e7 SHA-256: 4a1d04e3e7b8892176c2f15de981c97e3abd9344cc9629cfa23d35aa8a5ddea6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, with a high concentration of them being unknown or suspicious. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a deliberate structure designed to obscure the true destination or to maximize search engine visibility for malicious links. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://fsgzb.com/upfolder/e/files/20210907211159.pdf In PDF document text
    • https://alpinebadmintonacademy.com/ckfinder/userfiles/files/xivitutekobuw.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/31475599685.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/fukemedavaxitiravopedodim.pdfIn PDF document text
    • http://nitexprofi.cz/userfiles/file/46991661416.pdfIn PDF document text
    • https://aquamedicasatumare.ro/ckfinder/userfiles/files/44476223628.pdfIn PDF document text
    • http://snnet.kr/board_pds/fckeditor/2021/09/file/14437798332.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/zonureb.pdfIn PDF document text
    • http://www.village-gaulois.org/gestion/ckfinder/userfiles/files/19138940272.pdfIn PDF document text
    • http://visusmarble.com/images_upload/files/lokidazoxomebuwifopagire.pdfIn PDF document text
    • http://cngwalk.com/fckeditor/userfiles/image/vebod.pdfIn PDF document text
    • https://jewfri.kr/files/image/files/95597953677.pdfIn PDF document text
    • https://nhabe.com.vn/ckfinder/userfiles/files/bupopowoxe.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/46a2370118c9de5db89f0882590fb667/68308014948.pdfIn PDF document text
    • https://hv2barrier.com/application/third_party/ckfinder/userfiles/files/bujajilakukezenesus.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/madiwobakuvifibisuj.pdfIn PDF document text
    • http://alkanboya.com/files/file///lunamelet.pdfIn PDF document text
    • https://tavio.ru/files/file/82622532019.pdfIn PDF document text
    • https://westhygiene.hu/editor_up/potizugotorabop.pdfIn PDF document text
    • https://iwanbim.com/userfiles/files/8687334170.pdfIn PDF document text
    • https://nutstudio.it/userfiles/file/suwirokali.pdfIn PDF document text
    • http://life-worldwide.org/assets/uploads/files/xavunabidavi.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/62637920816.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=android+virtual+device+windows+10PDF 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_off0000e053.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE053 10768 bytes
SHA-256: bfd00d9b3c922dc5466de253533334a2e77d0240700c290f2862540839124b33
font_01_sfnt_off0000f95b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF95B 18192 bytes
SHA-256: 50fa04cfc638719c880936627da3752361c34c3f2437320e8de524559544b926
font_02_sfnt_off0001285d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1285D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1