Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b3a95f14afe9eaf…

MALICIOUS

PDF

74.8 KB Created: 2021-09-17 13:57:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 481138cddbbb7237227efb7028962e73 SHA-1: 8bc37abe31a7d404c567c7a0372392f638487cf2 SHA-256: 8b3a95f14afe9eafe3dde440bc37374273db3981a31abda2aa247cded5f718e0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external URIs, many hosted on compromised or disposable domains, suggesting an attempt to redirect users to malicious sites. The presence of URLs like 'https://smidgel.ru/uplcv?utm_term=rbx+get+free+robux' indicates a potential lure for scams or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=rbx+get+free+robux PDF link annotation
    • http://isdoor.ru/uploads/files/zunop.pdfIn PDF document text
    • http://security-m.jp/tool/images/file/xidikos.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/e4f3aa636c9e193c898458f7e2da14c0/debitexemide.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16143da971105b---tijalurijib.pdfIn PDF document text
    • http://rc-modeller.se/images/file///zaxomowamoladozowanulowum.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/sobexawadek.pdfIn PDF document text
    • https://topclassgardening.nl/images/file/92707149757.pdfIn PDF document text
    • http://kayapalinakliyat.net/file/14234018409.pdfIn PDF document text
    • http://letsbelegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/77881980156.pdfIn PDF document text
    • http://www.pvvc.cz/files/39257791788.pdfIn PDF document text
    • http://refinerlink.com/userfiles/file/figujiluxega.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/16141ff4288d8f---25458642803.pdfIn PDF document text
    • http://aquamedia.cn/ckfinder/userfiles/files/66878623299.pdfIn PDF document text
    • http://hotdeals24x7.com/ci/userfiles/files/55637823.pdfIn PDF document text
    • http://iuf.kr/pds_down/files/nevilovitududupiwo.pdfIn PDF document text
    • https://fullgame.hu/uploads/files/dewutipenolak.pdfIn PDF document text
    • http://nhanvietgroup.com/demo/xay-dung-tnx/upload/files/97454797292.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/1q7uo53itj4489c2ocr64rq67g/92514667257.pdfIn PDF document text
    • http://farashimirooz.com/files/nirepagumonamipopizeje.pdfIn PDF document text
    • http://simpelms.nl/userfiles/files/2710281908.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/64869552746.pdfIn PDF document text
    • https://anup.bo/images/files/1647943236.pdfIn PDF document text
    • https://tes-sys.com/uploads/ckfinder/files/20210915/16317137645708.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_off0000c361.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC361 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB73 16976 bytes
SHA-256: cfb5fea4ba953058fc28a87eda8cc4cc8341a74218ba6a01f0a1a09265eba765
font_02_sfnt_off000106cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106CC 10204 bytes
SHA-256: e3e73523c8dbc5e6d427b986274bc770a8eff79839f01e7f05cb8e159e28cbd1