Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc4e74eddcc7c420…

MALICIOUS

PDF

82.2 KB Created: 2021-09-19 09:50:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3692f84933fca873bbae9fa906cd727f SHA-1: 8996168c6a593b5386d06e1628794f5d93d79f0c SHA-256: dc4e74eddcc7c420c6f66bf220ce4b8fae2cd68871c823b83e57f594ddff05da
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as containing a link farm and was identified as malicious by a ClamAV detection and an ML classifier. The document body is heavily obfuscated, but the presence of numerous URLs pointing to various domains, many of which are associated with compromised CMS uploads or disposable hosting, strongly suggests a phishing or malware distribution attempt. The primary attack pattern involves directing users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://coretry.ru/uplcv?utm_term=crop+photo+apk PDF link annotation
    • https://incense888.com/uploads/files/202109120555569757.pdfIn PDF document text
    • http://highdeal.linkeo.net/ckfinder/userfiles/files/mowugigezebivejaparodeka.pdfIn PDF document text
    • https://rotitelor.com/contents/files/repekowuwinuk.pdfIn PDF document text
    • http://saeronbio.com/userData/board/file/vodugu.pdfIn PDF document text
    • http://snap-drone.com/userfiles/file/52123747229.pdfIn PDF document text
    • https://areopag.ru/sites/default/files/uploads/tutulavefe.pdfIn PDF document text
    • https://ofly.om-digitalsolutions.cn/upload/files/66800074580.pdfIn PDF document text
    • http://downtowncincyhotels.com/core_degree/admin/images/cms_imagesfiles/nuvofipezekujotatimekavi.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613729ea26be6---30731253803.pdfIn PDF document text
    • https://atavio.ru/files/file/10833063024.pdfIn PDF document text
    • http://braciszewska-klimek.pl/fck_files/file/78628052947.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161461a1b22f0d---fozapewapagojuzetosum.pdfIn PDF document text
    • https://copab.tn/216mag.svn/uploads/files/27511521302.pdfIn PDF document text
    • http://tulga.ru/editor/files/72853584183.pdfIn PDF document text
    • https://tekartltd.com/upload/files/kawune.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16136fc1512d03---fimot.pdfIn PDF document text
    • http://ranahytta.com/ckfinder/userfiles/files/72789870407.pdfIn PDF document text
    • http://ruihuitax.com/files/file/99850260399.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613edf742f155---73934740636.pdfIn PDF document text
    • http://xn--o79av69abka850ab6c.com/upload/file/202109061551258425.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/25950308643.pdfIn PDF document text
    • http://archidaldegan.eu/userfiles/files/34926721547.pdfIn PDF document text
    • https://schachverein-marchhoefe.ch/fcsr/news/upload/file/wevorepedinaf.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_off0000d5e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E4 9932 bytes
SHA-256: 0cdea03ffe466c763172ef17d9727d4295906f3185e8710efec42d495859f7b9
font_01_sfnt_off0000ebf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF9 21092 bytes
SHA-256: 367e3f958c2377063522e88420c982d251cc52e5fb328d6535329f77cc9fbe4c
font_02_sfnt_off00012313.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12313 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1