Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4286de56d6c4c96…

MALICIOUS

PDF

88.0 KB Created: 2021-09-10 18:52:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 35833f7f29b0cdb2671546efc84d0e9f SHA-1: 112debfc928d8bc7d6c439e19b390f668b2f020e SHA-256: b4286de56d6c4c96256fd1cf45fdafd17c2a5f2d20155cebdf0c46cbcd78a895
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple domains, including one identified as a compromised WordPress upload storage, suggesting an attempt to distribute further malware or redirect users to phishing pages. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • 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://master-br.ru/img/file/sosezaweloguvofujet.pdf In PDF document text
    • http://santeh.md/img/files/xosemopasubux.pdfIn PDF document text
    • https://ihappywash.com/uploads/files/202109030100472715.pdfIn PDF document text
    • https://congtydaihai.com/upload/files/zuxeruv.pdfIn PDF document text
    • http://studioarclab.eu/userfiles/files/valogupokerubonimad.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/dd3d40592e7db6a1f270c84026aebdf6/9755741073.pdfIn PDF document text
    • https://www.hkha.org/ckfinder/userfiles/files/lukeziritobememonalofufis.pdfIn PDF document text
    • http://dison.cn/filespath/files/20210904092731.pdfIn PDF document text
    • https://vildmarksjagt.dk/userfiles/file/vemekavaripoviwesiwaxamob.pdfIn PDF document text
    • http://talentfuturesservices.com/sharpinstitute/images/files/milipakememekenivatonesam.pdfIn PDF document text
    • http://solarexperten.ch/fckeditor/editor/images/file/lilodo.pdfIn PDF document text
    • http://csc0311.com/userfiles/file/20210906050949_fv2v5x.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/76773779107.pdfIn PDF document text
    • https://maharajganjtimes.com/assets/ckfinder/core/connector/php/uploads/files/zowexuketatajedokalab.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161318486ec0cc---vufaxuxivanuwugazupapi.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/vawolaxadikodove.pdfIn PDF document text
    • http://www.ondebiz.com/userfiles/file/disewujerine.pdfIn PDF document text
    • http://apexnepaltravel.com/userfiles/file/85959897065.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137d30416a80---pozerobatirir.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/lesared.pdfIn PDF document text
    • http://lafiestadelmoto.cz/files/file/9510477852.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/1s6kr98495kgr8q3vutk5lun33/novesosigoporur.pdfIn PDF document text
    • http://tnslib.net/userfiles/files/zujepikapilop.pdfIn PDF document text
    • http://serextion2006.com/js/upload/files/kitibuvosepuzabaf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=games+download+pc+free+windows+7PDF 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_off0000f09f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF09F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000108b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B6 10860 bytes
SHA-256: 4b8dade08efa7e5289c8a21a11e60dc785f1445413c720e67501a09445b28062
font_02_sfnt_off000121d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121D5 18836 bytes
SHA-256: 8fff354de7039b030a81e057be8be110cb740369217ea31ade2ad34706f31ef8