Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c10e6e1c81d0f5…

MALICIOUS

PDF

83.5 KB Created: 2021-09-14 14:18:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4b4025250b10c154ba536873622be57d SHA-1: c42a70ce83670eed7511551b2cdeba610578ea0d SHA-256: 51c10e6e1c81d0f596f4513b173f2b9740217d57221dc6469d43ae220e250619
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by multiple heuristics, including a high ML score and ClamAV detection, indicating malicious intent. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggest the document is designed to redirect users to potentially harmful websites. Although no scripts were explicitly extracted, the PDF structure itself likely contains embedded links or exploits that facilitate this redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://marwaautorepair.com/nbloom/fckuploads/file/89777094398.pdf In PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/98750044707.pdfIn PDF document text
    • https://vsetinrally.cz/userfiles/file/bepukajaxomuwixowe.pdfIn PDF document text
    • http://colorfulmedia.de/fotki/fotki/file/juzolifisanofujexezotixef.pdfIn PDF document text
    • http://rocb-ap.org/file_media/file_image/file/53592223242.pdfIn PDF document text
    • http://lidaoxc.com/upload/files/kitukilutorubujurazujus.pdfIn PDF document text
    • https://premiersuli.hu/files/files/rovuposufure.pdfIn PDF document text
    • http://giftboxvietthuy.com/upload/ck/files/35282834008.pdfIn PDF document text
    • https://marjoyunlar.com/calisma2/files/uploads/24484311169.pdfIn PDF document text
    • http://tech-sub.com/userfiles/file/81645841349.pdfIn PDF document text
    • http://giayviettri.com/img-ftec/files/zamizusigaxavorexorike.pdfIn PDF document text
    • https://mdteam.se/ckfinder/userfiles/files/78245623233.pdfIn PDF document text
    • http://abwplazaview.com/uploads/files/kisusif.pdfIn PDF document text
    • http://ain.proximeo.com/ckfinder/userfiles/files/xemofasepejebo.pdfIn PDF document text
    • http://primaria-ciocirlia.ro/media/file/74073578452.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/nujemumezu.pdfIn PDF document text
    • http://snbedu.com/uploadfile/file///2021090220504152.pdfIn PDF document text
    • https://kawanmto.info/contents/files/piviwaladimenewedoriwu.pdfIn PDF document text
    • http://abnig.friendship-match.com/upload/files/kidejadiwuwuvixodoj.pdfIn PDF document text
    • http://remproekt-m.ru/admin/ckfinder/userfiles/files/bumodabodagemonag.pdfIn PDF document text
    • http://sziazsauto.com/uploads/files/famesefok.pdfIn PDF document text
    • https://www.thaiahpa.com/flash/files/76540000594.pdfIn PDF document text
    • http://www.heksan.com.pl/file/7170503019.pdfIn PDF document text
    • http://agro-partner.com/Image/files/66632613228.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=counter+attack+mod+apk+unlimited+moneyPDF 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_off0000dcaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCAA 10844 bytes
SHA-256: daed6884559d84ca318deb59c2d6195238a19f45ff6d10913239e99a72a841cf
font_01_sfnt_off0000f5b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B8 19448 bytes
SHA-256: 9970741210e44ee2a7eceba64fdafb91afcee6c957440a755938a1c2bc2514ad
font_02_sfnt_off00012827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12827 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1