Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bd1d5f65337a506…

MALICIOUS

PDF

74.8 KB Created: 2021-06-13 12:42:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: aea1086b2a5c729742335838fcc333cb SHA-1: 731c3c1061ec01b2976eba1ae10634d29c9c61c1 SHA-256: 8bd1d5f65337a50691e7d0e4a165e10a0c86f6206890c46d902e031258b5fad2
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by 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 0.9999

Heuristics 5

  • 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=rangtaari+song+download+mp3 PDF link annotation
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/ceca974145142ee71290f1bce1dd4b94/29690576680.pdfIn PDF document text
    • http://bradleyhillsapartments.com/demo/uploads/contents/file/zokezesolekixusewutorev.pdfIn PDF document text
    • http://gintaras.cz/userfiles/file/59155683690.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/zuvinonojizokojegopubu.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608cfede00a4b---42548587799.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f641ca2db---83879240777.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d52ceade7e---55656969656.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/c0grjcfh74g0maas18q7v850k4/kufefedaduzewexuxupos.pdfIn PDF document text
    • https://www.makathastaliklari.net/wp-content/plugins/formcraft/file-upload/server/content/files/16081efb6b5aec---gumisonipanis.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/93b172dc8a37423b1b57be671d14183b/64287983166.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/1608cfceec9cc8---39779339237.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/dabexawul.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/27a4be5df17554b5b627495fca8b815f/diluviniwotivugu.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b65e6e14710---7714378681.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/f44359ede0fa157fab057c4f2d3219af/40830696607.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/7459ed089aef1de5953065d67a1d7432/30132728731.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6B2 5544 bytes
SHA-256: 1179c72e81099311603b21e20df2654e6727eef0bdc1d572bc57c9a6fc9c97c7
font_01_sfnt_off0000f993.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF993 10716 bytes
SHA-256: 1d0367656c168f5f9c8bb88ea115d3656a9f1a4c7c0f689ed84127ab5e3921b0