Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8c988a941612b2f…

MALICIOUS

PDF

71.9 KB Created: 2021-09-27 20:12:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 189f803c150932f3b778f670b4a9f353 SHA-1: 4c9c631973db084bc5416b650919424f263c3b70 SHA-256: f8c988a941612b2ff0b6c542aee5239bbbb5dd881a893048e52a305fb5ebd96d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://synerhu.ru/uplcv?utm_term=inverse+trigonometry+graphs PDF link annotation
    • http://greenhere.cn/upload/ckimg/files/202109100758525731.pdfIn PDF document text
    • http://spartapr.com/images/upload/file/suwesopixotofipizuw.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/gezifuxaxokiguzilaritona.pdfIn PDF document text
    • http://agriturismolataggiasca.eu/userfiles/files/65326904900.pdfIn PDF document text
    • https://topupdana.com/contents/files/popatijegemutakik.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ae0d129e41---konetapabufa.pdfIn PDF document text
    • http://mmsmarin.com/imgimage/file/mofavaxo.pdfIn PDF document text
    • http://thaimassagemodel.com/ckfinder/userfiles/files/80323642285.pdfIn PDF document text
    • http://tongshengchem.com/ckfinder/userfiles/files/12013528195.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/35816731285.pdfIn PDF document text
    • http://tokyosushilohaus.com/uploads/files/69504269986.pdfIn PDF document text
    • https://eletvital.hu/uploads/files/sutoveborije.pdfIn PDF document text
    • http://amsasecretariat.fr/userfiles/file/13555981689.pdfIn PDF document text
    • https://taiwan-tiaya.com/upload/tiaya_official/files/93957387245.pdfIn PDF document text
    • http://vocal.bpv.su/content/files/files/83484402071.pdfIn PDF document text
    • http://cec-intl.ru/app/webroot/files/file/51297493138.pdfIn PDF document text
    • http://gocreate.termall.pl/upload/fck/file/bosadivokorexa.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613758035dec5---paxegekikate.pdfIn PDF document text
    • https://culturasiapamplona.com/guiarte_userfiles/files/rokitibelili.pdfIn PDF document text
    • http://abw10thstreetne.com/uploads/files/nosizobarukigemunalatet.pdfIn PDF document text
    • http://hfnhsw.com/upload/files/33148223503.pdfIn PDF document text
    • http://abwmarlboropike.com/uploads/files/kovefotofomute.pdfIn PDF document text
    • http://bhavalaya.org/ckfinder/userfiles/files/kajiveranonajelukebiser.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_off0000b37e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB37E 10784 bytes
SHA-256: ee42c4f285c83f3f99b22441f68cdf119a58a36e19343980ced13c3d78a1962c
font_01_sfnt_off0000cc32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC32 17748 bytes
SHA-256: bcb67b11ab4c6ad075e3ed54aa895cc53f8093fddd63bbde27d5ea4f067c80dc
font_02_sfnt_off0000fa4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA4D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1