Malicious PDF — malware analysis report

Static analysis result for SHA-256 53149231cfac0c82…

MALICIOUS

PDF

160.5 KB Created: 2021-06-09 10:56:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 791c0bd63761e90a58f1ce9a776eedb0 SHA-1: 7713c3672b164483e85c503368664ddf16670425 SHA-256: 53149231cfac0c82ff665ae9b3e556c3ffa28b406008a8ac0ab73f6b67f0477f
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 0.9997

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=iwe+odu+ifa PDF link annotation
    • https://efnnma.org/files/file/diropuxikuraridezima.pdfIn PDF document text
    • http://meble-tk.pl/userfiles/file/pofuvumujuruwuweneresoz.pdfIn PDF document text
    • https://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/6d5626c0d3e11cdbd646d7f4b198bd98/joniwegazonotejari.pdfIn PDF document text
    • http://zonazero.es/userfiles/file/74982326095.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16080b96512120---senobez.pdfIn PDF document text
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609c2b164989f---ropixepekerit.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16096e10834d15---pofenagagetevameworev.pdfIn PDF document text
    • http://kath-kiga-bw.de/bilder/berichte/file/lenajegejusamaronuridema.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609800a753063---zepubaneze.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/fasokabegusudokaf.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/buxokupapem.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1609ea4d2a1b13---jinafonijoseditovuf.pdfIn PDF document text
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/486de3f4ccd4033de26149b79501560d/23554114657.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/1d1c1chqg42t4otdg00et5d8k5/zefurasaxasedexezewupab.pdfIn PDF document text
    • http://donaldnathanlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/55856740649.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607190745e7c1---25622477219.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160840ec62d7b1---wodimiwelowa.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/6037ce1c94877a1a2cc2e4ffb2611698/16264447775.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d8ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8AB 121468 bytes
SHA-256: a45c9b0646cad55930535417110a0929c49eb65cc54d586d404918268896b890
font_01_sfnt_off00023fe6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x23FE6 4624 bytes
SHA-256: 2cd7e79cce22eded1fb3bc38eb57222aa0a25042094798ada7e9737e8a44b303
font_02_sfnt_off00024fcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24FCD 10148 bytes
SHA-256: 9ba37d0a39b68153f1618fbd5b50f0a451a5c014589f84d935b3bb6327ac5027