Malicious PDF — malware analysis report

Static analysis result for SHA-256 85ccbce54aa23184…

MALICIOUS

PDF

100.9 KB Created: 2021-09-23 07:38:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3d146e949a93186239b8740f37cf812d SHA-1: cbdb8ab88a29d8f39f3c0fb9a1016d3d845887f4 SHA-256: 85ccbce54aa231847c9bbbd84b0449724c0b3957077abe241bc2bb66fd71670b
96 Risk Score

Malware Insights

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

The PDF contains a high number of external links, many pointing to compromised CMS uploads or disposable domains, indicating a link farm designed to redirect users to potentially malicious sites. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, but the structure and URL patterns are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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://pistant.ru/uplcv?utm_term=sonic+after+the+sequel+mobile PDF link annotation
    • http://stjconsulting.it/userfiles/files/80986384074.pdfIn PDF document text
    • https://eletroluz-al.com/_IMG/img_internas/file/64386699180.pdfIn PDF document text
    • http://bensonlandscape.com/editorData/file/nasalowevarinotokuru.pdfIn PDF document text
    • https://strings97.hu/userfiles/file/gufawikuju.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16131cfdd2d132---25288348157.pdfIn PDF document text
    • https://12shio2.com/contents/files/93845635732.pdfIn PDF document text
    • http://ansing.nl/userfiles/file/48648605087.pdfIn PDF document text
    • https://oasis-travel.ro/files/waxosowafatipukumin.pdfIn PDF document text
    • https://szamitogep-szerviz-javitas.hu/ckfinder/userfiles/files/87637469734.pdfIn PDF document text
    • http://twfindia.in/userfiles/files/vuladu.pdfIn PDF document text
    • http://www.fishandcosolicitors.com/uploads/files/selikubawemegoduris.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/pupirakazusonivewi.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/35a0e73477fa33bd18423c36a0fdc2b0/47196845374.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161356e8d0b7e5---jotebatirasijovom.pdfIn PDF document text
    • http://nbc.com.vn/ckfinder/userfiles/files/jajajuxibivevipunaralonu.pdfIn PDF document text
    • http://khamranghaiphong.com/upload/files/kesotowakovulokubuj.pdfIn PDF document text
    • http://vhshf.de/File/berugirogenojokitobujodop.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/vatonu.pdfIn PDF document text
    • https://llbyggodesign.se/UserFiles/files/riruxolusobawurexapazatuk.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7d838c5b3---26859436548.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/73703757480.pdfIn PDF document text
    • http://szkolka-wiercioch.pl/files/file/regefup.pdfIn PDF document text
    • http://kamennykoberec.eu/editor_uploads/system/files/70437266026.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/65652280299.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_off00011e66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E66 20844 bytes
SHA-256: 3d72d417bb149eb84424438720282688cf5b6d333ed342a098748fcc73c3c2fd
font_01_sfnt_off0001548a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1548A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016ca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16CA1 11060 bytes
SHA-256: 0a82037abfbbc5bcd6b67041941b0bd7caa1272c287c86420dc6b67fdc6caf8c