Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5cd8c0ed3c82619…

MALICIOUS

PDF

72.2 KB Created: 2021-09-30 20:03:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 3d750d38566afedf167323f531ce4a53 SHA-1: cfd77437fd89126f34f558953202cc2c3c90f9d1 SHA-256: a5cd8c0ed3c82619fdc367e71ced83073cf7d4f297a1035d52875911739dd444
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics as containing a link farm pointing to potentially compromised WordPress upload storage and disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. While no scripts were extracted, the document's structure and embedded URLs strongly suggest it is designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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
  • 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://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16142ec336dcd6---68175730265.pdf In PDF document text
    • http://lucchetta.net/userfiles/files/gopawuwusenofemin.pdfIn PDF document text
    • http://biosurfest.com/userfiles/files/jewidalomibufavibi.pdfIn PDF document text
    • http://www.otevrenysklep.cz/ckfinder/userfiles/files/18954296641.pdfIn PDF document text
    • http://www.ih-consultant.com/ckfinder/userfiles/files/23375983233.pdfIn PDF document text
    • https://xn--80aaijz0c.xn--p1ai/ckfinder/userfiles/files/nalizixizoreteziwazo.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/logovipitufidevi.pdfIn PDF document text
    • http://prmakeup.com/Image/files/45501695489.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/17908934197.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161486b8c5aebb---9112088269.pdfIn PDF document text
    • http://jncs.kr/page_data/file/20210909182743.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/lajozotepimemi.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613900532833c---99508778696.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/nj95gp9i2tefs2l7fnnnffbt2d/69915596305.pdfIn PDF document text
    • https://lotteppta.com/beta/assets/file/27182922956.pdfIn PDF document text
    • https://artedeeducar.com.br/ckfinder/userfiles/files/26413310698.pdfIn PDF document text
    • http://xn--42ci4cc0aric4a6dd7c5af9nef7sg.com/userfiles/files/11521024665.pdfIn PDF document text
    • http://gleb777.com/fck_upload/file/mojatode.pdfIn PDF document text
    • https://protrialse.eu/files/files/pukabisaretol.pdfIn PDF document text
    • https://pingthye.com/userfiles/files/potedubidevixelo.pdfIn PDF document text
    • http://ordineveterinarireggioemilia.it/userfiles/files/fotolilimukaletos.pdfIn PDF document text
    • https://ijestr.com/ckfinder/userfiles/files/5201567517.pdfIn PDF document text
    • http://afslab.asia/upload/files/27059895600.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=smashing+four+mod+apkPDF 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_off0000b4ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4EC 17732 bytes
SHA-256: 419c67f08f2d7740c4b96853b74527d548136d886e8b2739cf5aaf33eaf14d1d
font_01_sfnt_off0000e242.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE242 10936 bytes
SHA-256: 19f139b115374276e8ae204c8cbf68243ecdb499d094c90de24d79cd630fbc1b
font_02_sfnt_off0000fb20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1