Malicious PDF — malware analysis report

Static analysis result for SHA-256 efdf713e367dcabf…

MALICIOUS

PDF

93.0 KB Created: 2021-09-05 19:36:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 4a3888a3b9150f046bd3e9021dce51f3 SHA-1: cf4c1b0b6336e16ab06ba62b12f66db2bdd9e9a7 SHA-256: efdf713e367dcabf12948989f0fe51bd967ec661970ec6fa6d58efcc1968ee76
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/5g1g683lfj393e8venq51b0ha6/41247642366.pdf In PDF document text
    • https://konzolstudio.ro/uploaded_files/file/46014568540.pdfIn PDF document text
    • https://stijsr.com/userfiles/file/23910275326.pdfIn PDF document text
    • http://sierrahighalumni.com/clients/878712/File/60169499399.pdfIn PDF document text
    • http://wagnerpc.com/userfiles/files/57545920550.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606c920e9e7a0---77581655138.pdfIn PDF document text
    • http://didula.com/img/file/31631299871.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/xisozepuzodidovutolokuk.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084e6ff77547---29863571389.pdfIn PDF document text
    • https://tresonance.org/uploadfiles/28683626880.pdfIn PDF document text
    • https://turismopontevedra.com/ckfinder/userfiles/files/78006252290.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160850d36b5817---suridapesutakadetifitif.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/37790773226.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/64336935068.pdfIn PDF document text
    • http://www.kilincsweb.hu/fileok/file/fajikara.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/dabexov.pdfIn PDF document text
    • https://rosycaffe.com/file/3590681738.pdfIn PDF document text
    • http://geometrarontani.it/userfiles/files/sizux.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160aa593a3e104---wofonomadudejuzobigajiron.pdfIn PDF document text
    • http://alpha-th.com/userfiles/file/mevuvajuguzokepesem.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/11092750655.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/87f95a82d1d44e27e13e5549bba90c48/70574731962.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=cioms+v+pdfPDF 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_off00010531.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10531 10112 bytes
SHA-256: 4262941cc1f8791bfbeda2e65f9089573a40912447ef62e92616a53ea3e9fb81
font_01_sfnt_off00011bbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBF 19320 bytes
SHA-256: 068f6f65a14f64e82ef8ad9d89b4dffbb665badc0d0890e3dad9bbc0d3ddc085
font_02_sfnt_off00014ec1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EC1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1