Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ae90779640b61c1…

MALICIOUS

PDF

68.7 KB Created: 2021-09-25 01:26:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 2415b4467ba328291c8ee154ebd3ff25 SHA-1: aa4a9046ea6b523b2f421a7982a4ab9696a85b21 SHA-256: 8ae90779640b61c16ace1af3149998bfef6a0275a5b566e5f8f3b0091980f2e3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to disposable domains, suggesting a link farm designed to obscure the ultimate destination. While no scripts were extracted, the structure and numerous external links are indicative of a phishing or redirection attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nikkenj.com/userfiles/file/59616276187.pdf In PDF document text
    • http://kcemsp.org/upload/editor/file/dapiremodegodamaj.pdfIn PDF document text
    • http://gelikonline.ru/content/Files/gupakopadedijekoded.pdfIn PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/93828261610.pdfIn PDF document text
    • http://studiosiciliani.eu/userfiles/files/49923354439.pdfIn PDF document text
    • http://xn--rssx31a7tec6p.com/upload/userfiles/files/20210904155821.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/mudenop.pdfIn PDF document text
    • http://laptopplus.be/app/webroot/files/userfiles/files/maxufibozosurixutuk.pdfIn PDF document text
    • https://kvzriu.org/images/file/9591946718.pdfIn PDF document text
    • https://deloge-nt.fr/media/photo/file/kixuja.pdfIn PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/fenexavubub.pdfIn PDF document text
    • http://vitali-schulz-eiskunstlaufen.de/userfiles/files/wemabimedowakoxol.pdfIn PDF document text
    • http://fgosvo.ru/files/files/likagizokeronoganuj.pdfIn PDF document text
    • http://korea-seals.com/ckfinder/userfiles/files/kureso.pdfIn PDF document text
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/88957438690.pdfIn PDF document text
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/79117904319.pdfIn PDF document text
    • http://anael.fr/fckeditor/userfiles/file/rebifofujatixuje.pdfIn PDF document text
    • https://ntpuvoice.com/ckfinder/userfiles/files/79213434543.pdfIn PDF document text
    • http://drxzhang.com/userfiles/file/kefujajuzo.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/161447c2932196---23393637268.pdfIn PDF document text
    • http://1-cities.com/blog_images/blog_/file/93762656369.pdfIn PDF document text
    • http://yejida.com/userfiles/file/50242625484.pdfIn PDF document text
    • http://www.optimizecost.com/admin/ficheros_fckedit_subidos/23073120530.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d0b948cfec---27243134342.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=anime+mania+codesPDF 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_off0000afac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFAC 15228 bytes
SHA-256: 3ed3ac2dd01ea4c0db65d9dfbc16b5059e420972e028c2e50f5da4f919bb5caa
font_01_sfnt_off0000d691.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD691 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eea8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEA8 10268 bytes
SHA-256: efd408b28db8266834b93b7d56ff431304b6fdcbbe63d053b0d62bb66a1506a4