Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a1695cb3de0a3fc…

MALICIOUS

PDF

70.6 KB Created: 2021-09-12 18:50:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 60d370cee48420ccd2e08ecf0a5a5be7 SHA-1: 00276f90037c38e84e4c826a147ae9b562d0f42e SHA-256: 4a1695cb3de0a3fcd098a6b31247cfd8d4a582413bc3448e05100fff8f262a76
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of external URI heuristics and link farm indicators supports the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://teplo76.ru/uploads/file/dojijuzonomadonumosozivu.pdf In PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/9c49948fe8062042b93a10e2d85c2e00/wasaxekate.pdfIn PDF document text
    • https://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/62891125047.pdfIn PDF document text
    • https://villatoscana-pi.it/userfiles/file/6898238806.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efe0789ce2---kagax.pdfIn PDF document text
    • http://exosportsante.fr/ckfinder/userfiles/files/9782195587.pdfIn PDF document text
    • https://tucarrorentacar.co/ckfinder/userfiles/files/xijabew.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/202199235524421.pdfIn PDF document text
    • https://tagoproperties.com/ckfinder/userfiles/files/bezabuvumopizupex.pdfIn PDF document text
    • https://jooli.ru/ckfinder/userfiles/files/xavudebad.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/4vtkohpu5i44kfnn5r53mrq21v/75709017037.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/pezonuvizitunezulov.pdfIn PDF document text
    • http://liderzy.natura2000.pl/imgturysta/files/novosevidipukutowidaj.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161332d5d921ba---31085091732.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613b6bbac0b50---92155975970.pdfIn PDF document text
    • http://chukgoobok.com/files/fckeditor/file/45093987018.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/jakokajatelowadorolo.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/57b7032c8a429635ce127beb20a34ce9/89678999562.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/rewukupofosubesonotidu.pdfIn PDF document text
    • http://selidbe-beograd.info/files/roxada.pdfIn PDF document text
    • https://stotex.rs/files/xefelokefibugivumi.pdfIn PDF document text
    • https://unifor975.ca/userfiles/file/bisejasomudeg.pdfIn PDF document text
    • https://hkparkkonutlari.com/image/files/dokibo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=set+caller+id+androidPDF 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_off0000b639.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB639 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE50 10268 bytes
SHA-256: 390977c56c434ad9899d3603fc0f3b94791b0cf76e1c6f0e0865ef68810c7980
font_02_sfnt_off0000e57b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE57B 15624 bytes
SHA-256: 40c5ccdb1060bae698c4c9f957db7515419c96bedbf52152b8444f7bb9dfe776