Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b3e7b19275beef6…

MALICIOUS

PDF

78.4 KB Created: 2021-09-21 12:25:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 66268aee05479465a63939033bbe680f SHA-1: 41fa57f48dc95ad537314c47b7089b29977f3ed3 SHA-256: 8b3e7b19275beef691fb7c9c1eaca17f345273eb5e0e897fe9ed26633ac9b5b3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to obfuscate malicious destinations. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are consistent with a phishing lure or a downloader.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://noithatdangcap.vn/app/webroot/uploads/files/budidijovosinosevutul.pdf In PDF document text
    • http://lavalnerina.com/userfiles/file/zozarale.pdfIn PDF document text
    • http://tsg-edinstvo.ru/userfiles/file/38649485071.pdfIn PDF document text
    • https://mamotato.ro/userfiles/file/77822364333.pdfIn PDF document text
    • http://ntep2008.com/UserFiles/File/67636816974.pdfIn PDF document text
    • http://a-pluset.com/userfiles/gesabitibepeki.pdfIn PDF document text
    • http://teranor.com/ckfinder/userfiles/files/lolulonowowoz.pdfIn PDF document text
    • http://galaxyjewel.cn/uploadfile/files/xenegiwatovi.pdfIn PDF document text
    • http://nkmate.com/FileData/ckfinder/files/20210918_4AA327D8D474C942.pdfIn PDF document text
    • http://jca-t.com/fck_image/file/jomozedabefiro.pdfIn PDF document text
    • https://kawanmto.info/contents/files/lelegoninulegale.pdfIn PDF document text
    • http://dreamwith.gni.kr/ckupload/files/dafunada.pdfIn PDF document text
    • https://successstudio.net/userfiles/file/vadedurole.pdfIn PDF document text
    • http://sd-admin.fazendapenaazul.com/ckeditor/uploads/files/18891698304.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1613dbfb7bfea9---tesapasotupajubusugefaz.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/87379221556.pdfIn PDF document text
    • https://partnermind.cz/images/files/4015014086.pdfIn PDF document text
    • http://longvu.vn/Images_upload/files/selatomufekogavonuxikibun.pdfIn PDF document text
    • https://mytekas.com/UserFiles/file/55451277511.pdfIn PDF document text
    • http://www.hebrewforreadingcomprehension.com/content/bimegix.pdfIn PDF document text
    • http://erex.hu/upload/file/fakov.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/42f7c354c74fe6eee2eba06b20b64114/waserexevifelagaxazu.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0d1856d10---58312973263.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=friv+1001+gamesPDF 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_off0000c500.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC500 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD17 10300 bytes
SHA-256: 5f9dad49ea67e03c85790ad3a4a2ea9f6263ccb1c940f5af293aa0821caf4817
font_02_sfnt_off0000f460.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF460 21484 bytes
SHA-256: d4a61cb8c5ef52ca36cb5a6f861e633f2dbb50a7a631f8465ee51749ed4ff861