Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd7503155a4e9777…

MALICIOUS

PDF

80.9 KB Created: 2021-09-12 21:47:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 79e5aa0c52b20715942244af2b30f743 SHA-1: 8634e44d1b8fd7c47ec12d51e4f685f8289d47f5 SHA-256: cd7503155a4e9777cd291ae1945dac6727eb8314eedffe153e6a2fe56a577ec8
176 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to compromised CMS uploads and disposable hosting, designed to trick users into downloading further malicious content. Heuristics indicate a malformed exploit stream and ClamAV detected it as a phishing trojan. The ML classifier also strongly flagged it as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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 https://www.gurgy.net/ckfinder/userfiles/files/25677088055.pdf In PDF document text
    • http://ibconsulting.it/userfiles/files/39064229438.pdfIn PDF document text
    • http://defhjdrjioo.friend-match.com/upload/files/33133036612.pdfIn PDF document text
    • https://ylwlgwadmin.ylwl.cn/upload/files/wusakijetunef.pdfIn PDF document text
    • http://studiopedrazzini.eu/userfiles/files/67898715081.pdfIn PDF document text
    • http://easyreturn.store/userfiles/file/72145718639.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132750584bd3---84750087491.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b959e44be4---bolazomowu.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c5b19b36e8---zuluzapo.pdfIn PDF document text
    • http://jandebruijn.com/uploadimages/files/37961075797.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138b8996e637---91512312212.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/voxarowipudalaruxi.pdfIn PDF document text
    • https://value.ae/userfiles/file/jumasumetaza.pdfIn PDF document text
    • http://josephfellerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sumak.pdfIn PDF document text
    • http://kant21.com/userData/board/file/35988529013.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/lipamuwugoj.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/74732527850.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/sasuzideka.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/18581332964.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1613165ab3f6de---50928360776.pdfIn PDF document text
    • https://iieng.org/editor/ckfinder/userfiles/files/27362968668.pdfIn PDF document text
    • http://abwrichmond.com/uploads/files/2730320580.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=my+mxq+pro+4k+is+not+workingPDF 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_off0000d2f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB0C 10868 bytes
SHA-256: a4d672bd212353b5a21406164c7f48154c9f63c4879088a81028f76de0d3aec0
font_02_sfnt_off000103e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E8 18884 bytes
SHA-256: 7fcde44b8b5d55e3a657cb7299ae054984c49e5d1b40d6210907d9f99dea43f3