Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d3f9accdb9af8cc…

MALICIOUS

PDF

78.5 KB Created: 2021-09-15 19:36:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7d8c15383ea526595d2becd51de47fb9 SHA-1: e927ed84a1502055d23129f2a911a07e47da2938 SHA-256: 5d3f9accdb9af8cc8219dec231db292d417d0a9b8be8a21f9b616e026498a8a0
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple URLs, several of which are hosted on compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to lure users to external resources, likely for further exploitation or phishing. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://www.sherpachristain.org.np/ckfinder/userfiles/files/boleb.pdf In PDF document text
    • https://ghadir-eng.com/userfiles/files/94596566759.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139adc9a7901---litolirevepagi.pdfIn PDF document text
    • https://castilloexterior.es/ckfinder/userfiles/files/palemamunidiwusesifamulem.pdfIn PDF document text
    • https://brincandoeaprendendo.com/fotosempresa/files/37813071291.pdfIn PDF document text
    • http://vrieshorst.nl/images/uploads/file/nazivusupoki.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613797f85d89c---55742985762.pdfIn PDF document text
    • http://kenhuffbuilders.com/userfiles/file/45337632929.pdfIn PDF document text
    • http://dharmapuridiocese.com/svnprojects/DHD/Source/images/files/5032701221.pdfIn PDF document text
    • https://www.jnvhardoi.org/ckfinder/userfiles/files/luwufirasubunela.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee241d1718---sumokisasazunum.pdfIn PDF document text
    • https://hotelindigha.com/FCKeditor/file/tugusukebofesit.pdfIn PDF document text
    • http://www.asiacoservice.com/file/files/94989728456.pdfIn PDF document text
    • http://xszhuhai.com/uploadfiles/files/netotuvepinumetowupe.pdfIn PDF document text
    • https://anakaygame.net/calisma2/files/uploads/girezabog.pdfIn PDF document text
    • http://thanhtindesign.vn/uploads/image/files/sutojimexukag.pdfIn PDF document text
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/74230575472.pdfIn PDF document text
    • https://petrovsky14.ru/docs/files/16189516191.pdfIn PDF document text
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/72431646160.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613caee44eb4c---30596100951.pdfIn PDF document text
    • http://wellgroup.cz/UserFiles/File/27253520975.pdfIn PDF document text
    • https://unosms.us/userfiles/file/30815857224.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=bus+simulator+ultimate+offlinePDF 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_off0000d0e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0E2 10528 bytes
SHA-256: 49bdf5a4469a73e6681dfe66755691803f88f7c5d7fd5e7cc01d205e6518400b
font_01_sfnt_off0000e8e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E3 17024 bytes
SHA-256: 0f6cf6e89961c404ff5613e39c8514ac812be6131513f557c7b8a69da2ac9da3
font_02_sfnt_off000114eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1