Malicious PDF — malware analysis report

Static analysis result for SHA-256 813e75930bcec615…

MALICIOUS

PDF

77.6 KB Created: 2021-09-05 11:44:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: ccf44b23900e2401451d4d82c92096d2 SHA-1: 3c4ca711848509581b90a46c0b6f400437e89f17 SHA-256: 813e75930bcec615145b40ee3c6dfc184cbff9cf2c83bb2877796a4fbf86d657
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/f6a42a9fef45c0018c095a41b0f63533/2017253037.pdf In PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609071f60b0f4---jenulosimemonaguj.pdfIn PDF document text
    • http://hmconcretemixingplant.ru/d/files/vipenibesatere.pdfIn PDF document text
    • http://tysons-cafe.com/uploads/files/3706074461.pdfIn PDF document text
    • http://sy-smile.com/upload/files/poxano.pdfIn PDF document text
    • http://cokhisah.com/webroot/img/files/jokajuzapegogega.pdfIn PDF document text
    • http://stroytehcentr.ru/images/file/logimokokiroz.pdfIn PDF document text
    • http://csc025.com/userfiles/file/20210804001642_hk2mei.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/venepogutag.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b5178d3ca---kiwokajipilarazepadavu.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608251b9e8c07---nufasodaluxejiw.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e4826d0780d---33512288295.pdfIn PDF document text
    • http://ntouioc.ntou.edu.tw/ckfinder/userfiles/files/71568808601.pdfIn PDF document text
    • http://myphamnanyno.com/luutru/files/xunimi.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/160a2e7116cddb---5060209509.pdfIn PDF document text
    • http://residenzaeden-albisola.com/userfiles/files/pafavajeduzogewiluseduj.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/df6e832e6ff4a88eb52b920aac0ef4fc/jizotanexa.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/0751e81c075ce36d3e5c7b4cab1fc666/88610557492.pdfIn PDF document text
    • http://omegapizza.net/uploads/files/85242773388.pdfIn PDF document text
    • http://hi-techfiber.com/userfiles/file/8599692702.pdfIn PDF document text
    • https://blugarden.eu/file/66153442519.pdfIn PDF document text
    • http://lesen-und-schenken.de/userfiles/files/34957942055.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/160a370149e6f9---17614712755.pdfIn PDF document text
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/b1oi91bpkksfgl6cc7gsh6e7d6/xibawilotuviwetiwin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=tgt+english+syllabus+2018+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_off0000c1d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1D3 19820 bytes
SHA-256: 47ad2e5b7ec259fd15f699414b7dc4cb1f092f8164660ac789aef278c525da41
font_01_sfnt_off0000f5da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DA 11376 bytes
SHA-256: f63c36122dbede98c421dc62469a0a8c37ff3ebda537118b27638a0dec063093
font_02_sfnt_off00011046.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11046 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1