Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fc948a9d438c616…

MALICIOUS

PDF

87.4 KB Created: 2021-09-13 20:44:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ef6739ce7c529984751447806a31e9bb SHA-1: 25707cab2bd94a6fe52ecf232e954343181f4fa4 SHA-256: 4fc948a9d438c616dfedf1d3b50c40cbc96d0b884d21cc6a6f25c5bed7883bb6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting. Heuristics indicate this is a link farm designed to redirect users, and ClamAV detection confirms it as a phishing trojan. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=how+to+use+cleo+mod+in+gta+san+andreas+android PDF link annotation
    • http://thepnguyentran.vn/media/ftp/file/82329934162.pdfIn PDF document text
    • http://www.lebedosapartotel.com/data/yukle/files/86771341924.pdfIn PDF document text
    • http://irvinenott.co.uk/ckfinder/userfiles/files/20240194257.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/vuwenar.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9f99b8cff---60831060134.pdfIn PDF document text
    • https://vietnam-pump.com/userfiles/file/xanojodolawitezuf.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1613da7428a00f---36934914727.pdfIn PDF document text
    • http://cgmorenanews.com.br/ckfinder/userfiles/files/momifuwuruvesi.pdfIn PDF document text
    • http://falconfam.com/ckfinder/userfiles/files/64643393042.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/161359f6305f9a---nibabejizel.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-11/20210911061417913886.pdfIn PDF document text
    • http://atletika-pardubice.cz/files/file/wibisififetije.pdfIn PDF document text
    • https://www.passion-rnd.com/upfile/files/2021/09/09/46784887415.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/dukisezarijugijewof.pdfIn PDF document text
    • https://ww150005.linebot.net/upfile/files/20210908132310.pdfIn PDF document text
    • http://hockjoohin.com/admin/uploads/file/robuwes.pdfIn PDF document text
    • https://euinsuti.ro/app/webroot/files/userfiles/files/dimejoxux.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/aae7f4732f564f0ae1834094621f9f0b/rexuli.pdfIn PDF document text
    • http://casinodanmarkjackpot.dk/userfiles/file/63947111212.pdfIn PDF document text
    • http://brunagabriele.it/userfiles/files/35915835613.pdfIn PDF document text
    • http://af.ssla.ru/images/fornews/files/fivusaborawugogu.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/bodokibunovuletufafo.pdfIn PDF document text
    • http://proxima-online.it/public/file/biwebimaberojakudu.pdfIn PDF document text
    • https://apsco.ly/userfiles/files/49009942272.pdfIn PDF document text
    • http://saopauloairporttransfers.com/ckfinder/userfiles/files/jikamuvisibubamovabiruw.pdfIn PDF document text
    • http://hylimusic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/denizezutuvagoduma.pdfIn PDF document text
    • http://studiopol.it/userfiles/files/91997079241.pdfIn 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://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_off0000ee46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE46 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001065d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1065D 10892 bytes
SHA-256: acee3d9235a36a6d0724cd50cfaa81df62f65a54aef98aca20d107311d67b09f
font_02_sfnt_off00011f52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F52 18336 bytes
SHA-256: 3f5ac1e665ad6faa8f509ff56fb4677dad36070661470427a43166e34978539d