Malicious PDF — malware analysis report

Static analysis result for SHA-256 9e15a88bba14a99f…

MALICIOUS

PDF

81.3 KB Created: 2021-09-20 01:51:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ab30536e23599128308ef87ed36b7885 SHA-1: 9b7702861bf3bd4fe6b3429d212c6b37d02d7583 SHA-256: 9e15a88bba14a99f00d0a37abc3ca2bd9897064a65ac0394492b1409b8ed1abd
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to various domains, indicating a link farm. Several heuristics suggest these links are hosted on compromised CMS uploads or disposable hosting, and one URL specifically points to a compromised WordPress upload. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is used for malicious purposes, likely to distribute further malware or engage in SEO abuse.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://medvor.ru/uplcv?utm_term=123movies+websites+list PDF link annotation
    • https://vienhung.com/webroot/img/files/22760436769.pdfIn PDF document text
    • https://marbletreasures.com/uploads/image/files/78669398118.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1612f863e1be8f---24043151351.pdfIn PDF document text
    • http://forglass.sk/userfiles/file/13550533643.pdfIn PDF document text
    • https://coil.hk/upload/files/74829466720.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/tewopibawirixusezoxabubut.pdfIn PDF document text
    • http://fotocaroli.it/userfiles/files/sonotoxofeb.pdfIn PDF document text
    • http://lienming-rubber.com/uploads/files/202109061131585406.pdfIn PDF document text
    • https://tgvl.in/uploads/fck/files/50877588887.pdfIn PDF document text
    • http://pretaporter-pegah.com/userfiles/file/81128662928.pdfIn PDF document text
    • http://sanfrancescovet.com/userfiles/files/30325743492.pdfIn PDF document text
    • http://jplus-ag.com/upload/files/BodyFile__6144058C61288.pdfIn PDF document text
    • http://123podkrovie.sk/editor_uploads/files/tepajuvobilikovenof.pdfIn PDF document text
    • http://worldnaturalfood.com/image/upload/File/98822466811.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/f38ed208205af75911f298315629dc19/79989337300.pdfIn PDF document text
    • http://primeasset.hu/fileok/file/13274142409.pdfIn PDF document text
    • http://efcosmetic.com/uploadfile/files/nimazeg.pdfIn PDF document text
    • http://viral-list-monster.com/ckfinder/userfiles/publics/files/88129186208.pdfIn PDF document text
    • https://www.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/60870746018.pdfIn PDF document text
    • http://ke-sen.com/userfiles/file/1631480304.pdfIn PDF document text
    • http://professional-tuner.at/uploaded/file/bavitivutunozip.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614451c05d5fb---30588274804.pdfIn PDF document text
    • https://candica.pl/ckfinder/userfiles/files/51370232159.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/2160ca7d0220e0daa7483a16e073a7aa/vuvuzakikiwifosoko.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_off0000da8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA8B 17416 bytes
SHA-256: 3983bd1b75d1eb11d601a3513eabaee260d3032c5d20a992481f325e64977317
font_01_sfnt_off00010760.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10760 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F77 10440 bytes
SHA-256: ccd75e33e5d0b77e696cb3fe207be0f0b4cb0c5eac92d4b5ae1afe8159f6ddad