Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c622d019c1316ba…

MALICIOUS

PDF

70.3 KB Created: 2021-09-20 00:44:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 4bab87013a1260f59e1fd32298c27680 SHA-1: 2811128298771eeaf228de9b3c0d41f0f5c062d5 SHA-256: 1c622d019c1316ba6935d612d59ddce995224b48b56ded15896a7b5bccd98827
156 Risk Score

Malware Insights

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

The file was identified as malicious by a ML classifier and ClamAV, flagging it as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to various websites, including those on compromised CMS uploads and disposable hosting. The document body is unreadable, but the heuristic firings strongly suggest a malicious intent related to phishing or SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://honeystraw.com/uploadfiles/file/wexumupafugabowowibi.pdf In PDF document text
    • http://mybed.tw/uploads/files/202109101318591019.pdfIn PDF document text
    • http://e-district.org/userfiles/file/xisudexedowodemivesosete.pdfIn PDF document text
    • https://wecareprogram.org/images/file/jevib.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/1dmsqkdaq1ttshic5j9vpks7v4/guwipepexudowimemuvakixub.pdfIn PDF document text
    • http://kidneytracker.com/ckfinder/userfiles/files/xabegar.pdfIn PDF document text
    • https://phm.vn/upload/files/nipowebiwujefisa.pdfIn PDF document text
    • http://kamkmori.cz/ckfinder/userfiles/files/45439143869.pdfIn PDF document text
    • https://virtrade.gr/userfiles_lybo/file/nizenisonu.pdfIn PDF document text
    • http://haisushitogo.com/uploads/files/35171826578.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/49849825998.pdfIn PDF document text
    • https://rajakedua.com/contents/files/wutogi.pdfIn PDF document text
    • https://penzionradvanice.cz/res/file/95032580549.pdfIn PDF document text
    • https://netwindowvn.com/uploads/userfiles/file/69967392988.pdfIn PDF document text
    • http://an-professional.ru/img/files/file/nuvulijem.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16144bb2b73757---zupasaza.pdfIn PDF document text
    • http://marcelponjee.nl/ponjeefiles/file/dabili.pdfIn PDF document text
    • http://s2ipower.com/survey/userfiles/files/67687201808.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/70f21f2fbe18023664fdc613905179bf/62815655992.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16138eb37d7d01---96900936464.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/jifaridesa.pdfIn PDF document text
    • http://ptk-tent.ru/userfiles/file/gowiji.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/wujefurolefidu.pdfIn PDF document text
    • http://www.tempshift.com/app/webroot/files/uploadimagesfile/wivujelilisavusugijata.pdfIn PDF document text
    • http://studioboscono.it/userfiles/files/14651270761.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=cual+es+el+mejor+optimizador+de+juegos+para+androidPDF 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_off0000b4ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4AE 11056 bytes
SHA-256: 38fe107ddeed38cb5e9266c0f2aa66a598e711f9991d018936eb04f6785adecf
font_01_sfnt_off0000ce37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE37 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e649.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE649 14496 bytes
SHA-256: 4599c5c055e64e39d3fc0f534247fcffc78e78c8a8cf88085f848b84dad839ed