Malicious PDF — malware analysis report

Static analysis result for SHA-256 39fd78dd95058d36…

MALICIOUS

PDF

85.3 KB Created: 2021-09-03 18:49:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d70e9122ca895ddcf575630c83efe4f5 SHA-1: 4dc65d08f0e1da69b1af825df992081864e05c44 SHA-256: 39fd78dd95058d36a9ec14d64d970586b7e448adf19bdfdd7b0c688b4b35649a
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised CMS uploads and disposable hosting domains. The ML classifier strongly indicated maliciousness. While no scripts were extracted, the structure suggests a link farm designed to redirect users, potentially for SEO abuse or to serve malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://www.netcorp.hu/data/editorfile/81132975754.pdf In PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a81f84c95a7---4701447336.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/nejutuwoduwina.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/8f591dd6ebde79e0705e70b6d87b3c1b/fonajajubaxilored.pdfIn PDF document text
    • https://wedding-photos.cz/userfiles/file/84300800400.pdfIn PDF document text
    • http://pr-jam.com/ckfinder/userfiles/files/roboruzugo.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/8d821562bd98d5b8a85f38548f35c12f/gelunonaleturexufir.pdfIn PDF document text
    • http://nocleginaplus.pl/uploads/userfiles/files/84003759915.pdfIn PDF document text
    • https://funkydrop.shop/wp-content/plugins/super-forms/uploads/php/files/e2ae7c5c9def63fff95688379edf012d/fazigomobididope.pdfIn PDF document text
    • http://chinamakina.com/userfiles/file/40483189229.pdfIn PDF document text
    • https://umartravel.com/files/puziteginasigufeputaxaza.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160710d61379b0---28361571084.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4b0dfb2d82---piwoxizumiwurokokolu.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///98581771489.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e25f8c2b9ef---fovigok.pdfIn PDF document text
    • https://ptkas.com/kingkong/userfiles/files/kibafujudus.pdfIn PDF document text
    • http://airholic.com/UpFiles/WebEditorFiles/file/degafarepuxap.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3c2ccd213---bajevizivolu.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16117ce289a4c6---dopoxaderulobasax.pdfIn PDF document text
    • https://jiptv.nl/wp-content/plugins/super-forms/uploads/php/files/gi5crtalakl35b6ojp33jnqg7h/33354522834.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/gosifoxisobodoxakokem.pdfIn PDF document text
    • http://keluargamimpi2.com/contents//files/25800705094.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+become+a+successful+forex+trader+pdfPDF 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_off0000e3d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3D8 19656 bytes
SHA-256: 35e788156e27971a23341c7c7be0a4b2023bfeaec51afe0c72cfdba2c405724b
font_01_sfnt_off000115bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012dd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DD6 11004 bytes
SHA-256: 4dd7bcb25d2a9685b77aaa53fef7e44ac749a3e482e3afd9b27b7fd640ae2f35