Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac2cfc6a11b87e45…

MALICIOUS

PDF

77.3 KB Created: 2021-09-17 20:24:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 484ce4cf409b3ddc47154de8c5035588 SHA-1: 83ca576245b9b660d9b34a6ed3efe3fd406fa955 SHA-256: ac2cfc6a11b87e458245a86ba92fc15ef2c30e45cb230f345cd0a85a68b9e8d4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are hosted on disposable domains or compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest a phishing or malware distribution scheme. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

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
  • 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 https://synerhu.ru/uplcv?utm_term=ott+local+apk
    • https://lbk-ingatlan.hu/uploads/file/xobubewonunopike.pdf
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/mujowewajudojafezuj.pdf
    • http://box8websites.com/ckfinder/userfiles/files/63286294754.pdf
    • http://abyss.sk/userfiles/file/xumilelid.pdf
    • https://epponline.com/mentorfinancial/page_images/file/wutegorejogowizexuze.pdf
    • http://gulfapex.com/uploads/file/mimivijonezirifelezim.pdf
    • http://watch62.ru/files/files/23310530017.pdf
    • http://373113.linker.tw/files/bixurimaso.pdf
    • http://salamatekhanevadeh.ir/ckeditor/files/files/16948887663.pdf
    • https://amd-export.com/site/upload/file/63873116095.pdf
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161422691bc7da---21728235555.pdf
    • https://carmelocuritiba.com.br/ckfinder/userfiles/files/rupewoxotigoz.pdf
    • http://www.siscbolivia.com/admin/uploaded/fck/file/56617453834.pdf
    • http://librojuridico.com/aym_images/files/bodadugazofemusijemavuzet.pdf
    • http://www.hydro-tg.pro/upload/file/53614982074.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1613df600ceac1---64838377544.pdf
    • http://morebricks.com/ckfinder/userfiles/files/mabibukeg.pdf
    • http://1mosref.ru/ckfinder/userfiles/files/sitilekaxubinejele.pdf
    • http://jjw-led.com/userfiles/file/jodipamazil.pdf
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/wojifofisokubo.pdf
    • http://phuongdonggolf.vn/app/webroot/uploads/files/jowonabagadazujeruv.pdf
    • http://cargologicru.com/sadm_files/notafapaxanamugajule.pdf
    • https://asset-books.com/userfiles/file/vugewuxenafipepupegasuva.pdf
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/512cc9bb19320d3c06ab08c569775a70/5176468967.pdf
    • https://fainitelecommunication.com/public/editorfiles/file/88861046434.pdf
    • http://adance0112.com/upfile/editor/file/94976909222.pdf
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9b0d6801f---37705160138.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c7f1.bin
f4675690e4628975154de2483eb703f6100d95f08dd4fdc3af67182c21a594de
pdf-font-stream PDF embedded font (sfnt) at offset 0xC7F1 18484 bytes
font_01_sfnt_off0000f84c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF84C 16792 bytes
font_02_sfnt_off00011062.bin
2f0fea88b15e48e24b2817f39c2b9b822cd5806c9599e5f23445600cf12e4812
pdf-font-stream PDF embedded font (sfnt) at offset 0x11062 9888 bytes