Malicious PDF — malware analysis report

Static analysis result for SHA-256 6d43b06426eb3db3…

MALICIOUS

PDF

84.5 KB Created: 2021-07-08 05:12:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 4ccd09e361b11533e23d1ca924251404 SHA-1: 1e94aa7f1084098e6cff4dc9833ba2b664f3f2e8 SHA-256: 6d43b06426eb3db32768fd4dbeda0fa817384d0d6896d6ec30efcd5edd5cb473
96 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised websites, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external URIs and link farms on disposable hosting further supports this assessment. No scripts were extracted, but the overall structure suggests an attempt to leverage compromised infrastructure for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://coretry.ru/uplcv?utm_term=information+technology+test+questions+and+answers PDF link annotation
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd9075764c---lipopapakevuzibaso.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/4665dc60c284d0d2b4b9f9beb0addfc3/mumixunu.pdfIn PDF document text
    • http://trustarshida.co/cache/fck_files/file/mezelajolukunazinadudote.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb9f5cb631---82547384734.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16073b06c1e574---13791833100.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160783baedd927---zebemaxazumigipo.pdfIn PDF document text
    • http://zpb-maciejewski.pl/upload/fck/file/17993004020.pdfIn PDF document text
    • http://chalappuram.com/userfiles/file/32495185063.pdfIn PDF document text
    • http://trungtinjsc.vn/upload/FCK/file/49077915064.pdfIn PDF document text
    • http://momsystem.ru/public/file/17625465452.pdfIn PDF document text
    • https://sahodayabbsr.com/test/fckeditor/file/wuvulotexudomeveg.pdfIn PDF document text
    • http://funperm.ru/content/file/ziparipikamiwewisuruj.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/9a50680f3e837837f7e186a4c777345d/lituwugovi.pdfIn PDF document text
    • http://mebelhotel.ru/userfiles/files/66137466089.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/gt6odq0t6lrek6a6jhtl323aj2/lotafolem.pdfIn PDF document text
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/4omdbc14p126ue13em79h6hrrr/vojukitoxipak.pdfIn PDF document text
    • http://jmestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pitewebenanidemarit.pdfIn PDF document text
    • https://cihangirhotel.com/upload/ckfinder/files/vipep.pdfIn PDF document text
    • http://arablift.net/userfiles/file/4889121804.pdfIn PDF document text
    • https://pathakpharma.in/singhania/downloads/file/91792576824.pdfIn PDF document text
    • https://www.perfumista.co.uk/wp-content/plugins/super-forms/uploads/php/files/dbaecbe232f73ec71197500c5c27a0e6/somipopo.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/d913f1bafa7a551bde2691d4d2a6995f/mojozo.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/0649632f473997f1cb75c775378dd5be/83903252041.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_off0000e58b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE58B 11320 bytes
SHA-256: 73a2263af4bf05a0cfd781c9538fda68043b18401ebc9535e3e89b70cc239644
font_01_sfnt_off0000ff87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF87 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011799.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11799 17228 bytes
SHA-256: b84d81862034a480a1cfc5786f0d9c0e551672a692d82cf1a8a5c3952091e083