Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfbf1c6c20851505…

MALICIOUS

PDF

81.4 KB Created: 2021-09-13 20:45:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1d6087a43fa2938dd134934073b9d40d SHA-1: d7a0bb1f2013490533c33c558a4ee308630e777c SHA-256: dfbf1c6c20851505dc5126df854fe3dfc1dca11c9ada1da0773b144201282796
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for executing malicious code. The PDF also hosts a link farm pointing to multiple domains, many of which appear to be compromised WordPress sites or disposable hosting, suggesting an attempt to distribute malicious content or phish users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of its attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://12shio5.com/contents/files/puginanegid.pdf In PDF document text
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/83290994951.pdfIn PDF document text
    • https://residenciasanamaro.es/userfiles/files/54283355832.pdfIn PDF document text
    • https://bishopsalamatkhokhar.org/userfiles/file/92077592950.pdfIn PDF document text
    • https://www.mds-horizons.com/upload/files/97779628126.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/23089605349.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210910_4F0249B66070B54C.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/4g0da9gmu2r07rpfdjrbmkkrnn/61811683779.pdfIn PDF document text
    • http://www.erealitysolutions.com/tennisontario/assets/appsadmin/js/ckfinder/userfiles/files/10637984372.pdfIn PDF document text
    • http://nensi.si/upload/file/82183995919.pdfIn PDF document text
    • https://cvssteelex.com/ckfinder/userfiles/files/7027955543.pdfIn PDF document text
    • http://www.kowel.com/ckfinder/userfiles/files/1631014183.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/829fadcb9419db2961a7595479d94cab/85966947081.pdfIn PDF document text
    • https://oncallanatomist.com/ckfinder/userfiles/files/72257172235.pdfIn PDF document text
    • https://cmottaviproductive.it/uploads/file/lakosusimikejit.pdfIn PDF document text
    • http://alfonsoguiggiarchitetto.it/userfiles/files/gireso.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/fca429d371a665f0d9888c21225e18d9/zemiz.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/55455315363.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16134e994ad456---gidisamo.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/a1a0a73d3a6764a6a41653117dfffa05/nipolexezurumud.pdfIn PDF document text
    • https://cytairtool.com/test/userfiles/file/20210914_5a0dd.pdfIn PDF document text
    • http://etre-belle.su/images/file/31746862327.pdfIn PDF document text
    • http://hublihorse.com/uploads/userfiles/files/rikowazigomigavujawuvoga.pdfIn PDF document text
    • http://risorsaterra.it/userfiles/files/sonowewajalewerameb.pdfIn PDF document text
    • http://runhouchem.com/upload/files/61823002609.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613de2f2c0a65---ganigivosudeginex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=processor+wallpaper+for+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_off0000d948.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD948 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f15f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF15F 10604 bytes
SHA-256: 9300cea08928493e2cfec5aa4e04326225609efaf2372bff3a135920cd876a75
font_02_sfnt_off000109bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109BB 17508 bytes
SHA-256: 6e386b3c156d144978a0bf7d354c6e6424310271be2d98289f0983796fab32f9