Malicious PDF — malware analysis report

Static analysis result for SHA-256 0658a772d77f8a71…

MALICIOUS

PDF

83.7 KB Created: 2021-10-18 12:35:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ca466836edd7964d93396c526b4cee6b SHA-1: 9dca9409e40a465e0ef1411cd7acad7341d6fa4f SHA-256: 0658a772d77f8a719b613ce81965475718755d879283a2126e831d84480ca806
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as a phishing trojan and by an ML classifier. Heuristics indicate it functions as a link farm, with several URLs pointing to compromised WordPress upload storage and disposable hosting. The document body is heavily obfuscated, preventing analysis of its direct content, but the link farm nature and compromised hosting strongly suggest a malicious intent to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://hfbee.tw/upload/ckfinder_temp/files/20210921102718.pdf In PDF document text
    • https://ymvii.com/admin/upload/files/63589884375.pdfIn PDF document text
    • http://iglozawiercie.pl/zdjecia/file/1911051131.pdfIn PDF document text
    • http://geomanteia.com/userfiles/files/japomixosimomid.pdfIn PDF document text
    • http://www.f2dassociates.com/userfiles/file/48549291418.pdfIn PDF document text
    • http://surmounttravel.com/userfiles/files/25946090423.pdfIn PDF document text
    • http://fgosvo.ru/files/files/96127521259.pdfIn PDF document text
    • https://www.ewdel.cz/ckfinder/userfiles/files/jikawovurelupunuxa.pdfIn PDF document text
    • http://tai-group.com/upload/files/dovuwubemu.pdfIn PDF document text
    • http://surtek.biz/image/files/20150326_163730.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/9d6rua4pgtsa226i4j7psc67ql/79684131888.pdfIn PDF document text
    • https://lufty.cz/UserFiles/files/luxet.pdfIn PDF document text
    • https://hoya.hr/UserFiles/file/zofoxazusoxezimi.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153d04848198---tolumabewagavaxawip.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/161401bef46219---98609399471.pdfIn PDF document text
    • http://probeg2000.ru/files/userfiles/files/54784231844.pdfIn PDF document text
    • http://jatechkj.pl/upload/fck/file/33699626346.pdfIn PDF document text
    • https://tyeetomsfishing.com/userfiles/file/filorogaloxetozojeku.pdfIn PDF document text
    • https://kurashi-kyoiku.com/cms/dat/upimg/file/papinevozetok.pdfIn PDF document text
    • http://tropo-design.com/ckfinder/userfiles/files/mogurapujupodofopenezuk.pdfIn PDF document text
    • http://musikpark-live.de/userfiles/file/21195986531.pdfIn PDF document text
    • https://www.douggoodkin.com/admin/ckfinder/userfiles/files/70965695861.pdfIn PDF document text
    • http://phulieumaymacbaoco.com/hinhanh_fckeditor/file/76329498946.pdfIn PDF document text
    • http://fusheng-vietnam.vn/admin/webroot/upload/image/files/5886726594.pdfIn PDF document text
    • http://bronnicy.inhome360.ru/admin/ckfinder/userfiles/files/3600035894.pdfIn PDF document text
    • http://gpsputhuppally.com/userfiles/file/zokosizorupan.pdfIn PDF document text
    • http://pincesorvarshop.hu/editor_up/vobuberifiwotaluvulatove.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/u-9XGpgKpwY/uplcv?utm_term=writing+task+2+topic+environmentPDF 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_off0000e0af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f8c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C1 17648 bytes
SHA-256: 4792943c1dc918b2b109cad4a6d056e61683d5193dbca65a467a3eb7826d582d
font_02_sfnt_off00012607.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12607 10944 bytes
SHA-256: 0113f63727d1e3a6c027022979977444d719d023974654e458ddd53a692dbd8f