Malicious PDF — malware analysis report

Static analysis result for SHA-256 f731ecc6aba0db5c…

MALICIOUS

PDF

87.8 KB Created: 2021-09-22 14:46:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 37b3c928d9b5582cb66f3864a68d1770 SHA-1: 8d6c68b2840a23ae5be912abad5bdd5a300e86da SHA-256: f731ecc6aba0db5cb89fe3b0dad3e8d09be1dd6adc57e6c4a987ab8e9e42a9ed
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which are hosted on disposable domains and appear to be part of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns suggest it's used to facilitate the download of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9765

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://crewmak.ru/uplcv?utm_term=dream+league+soccer+2021+download PDF link annotation
    • https://rotitelor.com/contents/files/xipizeguxu.pdfIn PDF document text
    • https://flomogroup.com/upload/files/57881864058.pdfIn PDF document text
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/toviwoluvafonota.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16137c8e78b387---gisegokivusijirat.pdfIn PDF document text
    • https://afgventuregroup.com/cfiles/file/kinabudevomibumixexe.pdfIn PDF document text
    • https://pielinks.com/UserFiles/file/40177899156.pdfIn PDF document text
    • http://quangphong.vn/uploads/image/files/tajenadojigopibovulurak.pdfIn PDF document text
    • http://xinyaoqiye.com/upload_fck/file/2021-9-9/20210909125008985796.pdfIn PDF document text
    • https://manusingh.org/scgtest/eec-new/codelibrary/ckeditor/ckfinder/userfiles/files/vigasixujanetiwesonevigo.pdfIn PDF document text
    • http://egitara.com/upfiles/files/25208211658.pdfIn PDF document text
    • http://spl-designs.com/ckfinder/userfiles/files/48734596964.pdfIn PDF document text
    • http://esangsok.com/upfile/files/5111718249.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613d91f48580b---delirid.pdfIn PDF document text
    • http://villapellegrino.it/userfiles/files/fisimiruwewa.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/19114731613.pdfIn PDF document text
    • http://creative-format.com/upload/editor/files/sufolowevorikiviwu.pdfIn PDF document text
    • https://himalayanthailand.com/image/upload/File/tavonuzivamirub.pdfIn PDF document text
    • http://cyklo-sport-servis.cz/UserFiles/File/bufig.pdfIn PDF document text
    • http://kfbma.org/files/fck/file/87792700278.pdfIn PDF document text
    • http://masonhn.com/d/files/bipuwevemexuv.pdfIn PDF document text
    • https://aakritidigitals.com/userfiles/files/84734770748.pdfIn PDF document text
    • http://sdes.in/uploads/49527930533.pdfIn PDF document text
    • https://gs-hemeringen.de/ablage/userfiles/files/62265070125.pdfIn PDF document text
    • http://insei.eu/userfiles/files/13287946974.pdfIn PDF document text
    • https://toppelletmachine.com/d/files/12973677414.pdfIn PDF document text
    • http://www.gamylai.vn/uploads/files/vejigezobuwekonuvupedite.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d875.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD875 18584 bytes
SHA-256: 526e75ddbbf8b057a316b09076500dd7df5135cff37337b13d4202565b0ba831
font_01_sfnt_off000108ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108EC 16448 bytes
SHA-256: 0e4cde3d5bdd5452960de995a4807c8da4ec665155a9812e2f8e54e6c49b7878
font_02_sfnt_off00011fc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FC6 11004 bytes
SHA-256: 98feccae1132b6fca97433d5fe8bbbdff432afeab59cee7c5fb8d67b604d2a15
font_03_sfnt_off00013951.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13951 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1