Malicious PDF — malware analysis report

Static analysis result for SHA-256 421dd632ef3fdf79…

MALICIOUS

PDF

84.1 KB Created: 2021-09-17 08:21:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0b7bbbfbb09f60371db2de39d1005a44 SHA-1: 4de05ad8ac012ebd27bff8f5afe6ea559c99d903 SHA-256: 421dd632ef3fdf799a31cd02ce111553016dba22c15f55d12e47bfbd3b7d30ca
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to potentially malicious sites. The presence of external URI heuristics further supports this, as the document likely attempts to exploit vulnerabilities or trick users into visiting these external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://morebricks.com/ckfinder/userfiles/files/63143764600.pdf In PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f460f3553f---55227532140.pdfIn PDF document text
    • http://fsnmmaterials.com/UPFILE/userfiles/files/pujevuzefewen.pdfIn PDF document text
    • http://music-saikung.com/ckfinder/userfiles/files/53879736429.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcbe4587c8---14044881404.pdfIn PDF document text
    • https://sarna-zapiekanki.pl/ckfinder/userfiles/files/87819278693.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/19779414809.pdfIn PDF document text
    • http://pressvaluation.net/FCKeditor/editor/filemanager/connectors/userfiles/file/54873264308.pdfIn PDF document text
    • https://comfort8889.com/upload/files/56222312106.pdfIn PDF document text
    • http://rheinmotel.com/userfiles/file/tuvokuk.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/44913529049.pdfIn PDF document text
    • http://prplus4u.com/ckupload/files/besunonezogufebap.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/21706291618.pdfIn PDF document text
    • https://ilonew.tasksplan.com/userfiles/files/15285116612.pdfIn PDF document text
    • https://cuatudongsaigon.vn/uploads/files/18105146379.pdfIn PDF document text
    • http://vngo-cc.vn/cooker/public/files/maxapirulaje.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/niwuxuve.pdfIn PDF document text
    • http://skkl.cn/filespath/files/20210902133109.pdfIn PDF document text
    • http://engineersclasses4competition.com/files/others/95511447579.pdfIn PDF document text
    • https://taipeitccia.org/CKEdit/upload/files/maponosolotomok.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/7pvoc0vun0m3mh1kkrsv27sird/nunugu.pdfIn PDF document text
    • http://murasakijr.com/uploads/files/2362866587.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/sisevefesizomivutojidobaz.pdfIn PDF document text
    • http://373113.linker.tw/files/14441321576.pdfIn PDF document text
    • https://anthonygillant.com/userfiles/file/48117283066.pdfIn PDF document text
    • https://volgogradexpo.ru/ckfinder/userfiles/files/manukiwefozavebulupimewa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=child%27s+play+1998+full+moviePDF 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_off0000e397.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE397 11232 bytes
SHA-256: 6f4cad2694e43dc5cd7a4dba64b354fc0c8eebb53f833d42c0ea972201f963e2
font_01_sfnt_off0000fe12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011624.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11624 17096 bytes
SHA-256: c1c8f25f8d191b31b91604a93072552d559acd3c96831c09238579515096064e