Malicious PDF — malware analysis report

Static analysis result for SHA-256 e5ea3f3860e329fd…

MALICIOUS

PDF

84.5 KB Created: 2021-09-13 18:56:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a21943b3b63e140708a425cb0e6a53e6 SHA-1: ac534f0fb32a2b3fa0383931b39d33684ef4ca43 SHA-256: e5ea3f3860e329fde9f2044c269e57f26dd79342d2bdfedb419256df5789550d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM firings strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://parvazyab.net/basefile/api203/files/rewajubefebugufu.pdf In PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/7df7d88b353fd463dcb30dd61fcebe5b/88007882621.pdfIn PDF document text
    • http://isystem.hu/userfiles/file/94162147695.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-1/20210901082802333719.pdfIn PDF document text
    • http://shahnawazonline.com/uploads/files/pixawobelewuniximagomimu.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1612eead742b09---wovugepudedunapelono.pdfIn PDF document text
    • http://directartdeal.com/uploaded_files/userfiles/files/galigamatugolediniw.pdfIn PDF document text
    • https://dnm.tw/uploads/files/202109030058462640.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc83aecf77---wixalofojogaxas.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b515dc1eb0---zagufekamilelirawufov.pdfIn PDF document text
    • http://metalltechnik-kutschi.at/85668153417.pdfIn PDF document text
    • http://espwireless.net/uploads/file/pubowiwibenadufenuten.pdfIn PDF document text
    • https://helices-evra.com/userfiles/file/67400171794.pdfIn PDF document text
    • http://archiw.gbpopatowiec.pl/img/upload/files/79969893820.pdfIn PDF document text
    • http://dachastyle.com/userfiles/file/24454066890.pdfIn PDF document text
    • https://lbk-ingatlan.hu/uploads/file/jijudu.pdfIn PDF document text
    • https://egyptsuntours.com/userfiles/files/durisavabasobu.pdfIn PDF document text
    • http://obasekiestates.com/UserFiles/file/2086126970.pdfIn PDF document text
    • http://karimeh.com/public/userfiles/file/29425907193.pdfIn PDF document text
    • https://0922.sproname.com/files/userfiles/files/32554037632.pdfIn PDF document text
    • http://studiotecnicopetrillo.eu/userfiles/files/limifikaweziker.pdfIn PDF document text
    • http://thesecurityguardunion.ca/userfiles/files/78126456441.pdfIn PDF document text
    • http://teleinwestor.com/userfiles/file/26656692817.pdfIn PDF document text
    • http://gloria-eurex.com/images/blog/file/90963758545.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=web+service+android+studio+examplePDF 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_off0000d93e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD93E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f150.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF150 21844 bytes
SHA-256: bc4f17ea0948c624659e6980e6626f96f5e627e6473571888e1c56be3f58af91
font_02_sfnt_off00012ac8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AC8 11076 bytes
SHA-256: 2c626124485aff2af096ad33df2d43769fea1f2436f6113b86d6619b7d0eeaef