Malicious PDF — malware analysis report

Static analysis result for SHA-256 76838cdaf030d863…

MALICIOUS

PDF

72.3 KB Created: 2021-09-05 13:12:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: bd3af56d782e9f53e361ad990cdd750b SHA-1: 62d759a394dc3a12d9f6fb515c4eab601d5b95f2 SHA-256: 76838cdaf030d8633db1192901e4703486e96192bce81fff0edcf3875740e73c
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many pointing to compromised WordPress sites and disposable domains, suggesting a link farm or SEO poisoning attack. The ML classifier strongly indicates maliciousness, and the structure is consistent with documents used to distribute further malware or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://allytemp.ru/uplcv?utm_term=remeha+avanta+18v+boiler+manual PDF link annotation
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/77d1e6bc02b1b11b8b0ecb7801c6b162/55459357362.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d62aa324fc---76924635688.pdfIn PDF document text
    • http://kaies.cn/upfiles/21070214204493926975md2x.pdfIn PDF document text
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/5624115949.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/5f6372298d04395498dc82e337fc094d/wevopajupalofizaxefa.pdfIn PDF document text
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160819ac5bd65b---jimanegogexemo.pdfIn PDF document text
    • http://limobebe.com/userfiles/files/fatalejalafipoginafo.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/gizoba.pdfIn PDF document text
    • http://nesemlak.com/test/images/uploads/files/gisibipadufos.pdfIn PDF document text
    • http://elfuklid.cz/foto/Image/file/7713098072.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1607e9973a9f61---suwozivifumozobupivugos.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/68873318377.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/37811799606.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/lunorimaxupodoxixeda.pdfIn PDF document text
    • http://sushiloverca.com/uploads/files/zezodowevi.pdfIn PDF document text
    • http://ty-int.com/files/files/rozuxegoxusonozosaselas.pdfIn PDF document text
    • https://gamaconsultores.cl/upload/file/12324589596.pdfIn PDF document text
    • http://5m-tti.com/uploads/image/files/lawikorofunejuzelonabakuz.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/09eed35d6f151f5a94e9cf39d7fa7a94/10051818165.pdfIn PDF document text
    • http://kanchanaspa.com/ckfinder/userfiles/files/besepariwusunugi.pdfIn PDF document text
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/1e501604dd078d2234e412b7c983ef6d/sopabuxisamaror.pdfIn PDF document text
    • http://thesetnews.com/images/fckeditor/file/9208135565.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610345d318459---witumilaxarow.pdfIn PDF document text
    • http://imbirimbir.ru/files/36372347443.pdfIn 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://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_off0000b7c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cfda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFDA 10816 bytes
SHA-256: 72ab001d0f3c583ef26924c46c84980b585b4bd24f1d51c5753b58ad85ca38b9
font_02_sfnt_off0000e8a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8A1 16648 bytes
SHA-256: 17209ad358d59c835b245576a9c89f098315b3e67c0e77fe44fb9a68399ea6ec