Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecfc838bd0c6d38a…

MALICIOUS

PDF

77.7 KB Created: 2021-10-04 17:48:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 34e9b48985654273cf5f0c7d0a9dab74 SHA-1: 2c9b80338cb4b8f2f002471260a59a82bb30665a SHA-256: ecfc838bd0c6d38ab072c7b507547e92806f4cfbd6d6656049c55197aca859f2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://crewmak.ru/uplcv?utm_term=crossed+out+eyes PDF link annotation
    • https://radekslodkiewicz.pl/files/file/gixojegonatezaji.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/rugenuvevawopa.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1613854e779c7c---61300180336.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/8eh30djn898ltlu9rauj0sssao/boforozojivodetedatarakez.pdfIn PDF document text
    • http://zge-led.com/luodan/images/userfiles/file/38031361638.pdfIn PDF document text
    • https://icbacademy.com/upload/files/xitumaxo.pdfIn PDF document text
    • http://ayurveda-shiatsu-nice.com/upload/files/wazemosozifewaxobatokijo.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///20210909122715_148584106.pdfIn PDF document text
    • http://gazdalkodjokosan.hu/img/userfiles/file/zajowerotudidunigerijasux.pdfIn PDF document text
    • http://geobigoni.it/userfiles/files/53921629555.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/18ipkngcv4l4q2273ontrb6a42/togituzon.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613026e19fe20---65851474817.pdfIn PDF document text
    • http://vibrator4you.cz/UserFiles/File/zekurutalowore.pdfIn PDF document text
    • http://nut-shell.net/upload/files/75454427931.pdfIn PDF document text
    • http://tekizolasyon.com/ckfinder/userfiles/files/jerararemofirakupusi.pdfIn PDF document text
    • https://wedding-photos.cz/userfiles/file/wewikikipafajanajivekefa.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/gisixepavigivewegevanoxej.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/wesemujomuretefulipa.pdfIn PDF document text
    • https://tutorsbureau.net/userfiles/file/87320229725.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/23205947219.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613861ba036fb---guvawojenixixefukolol.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_off0000ce8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE8D 10080 bytes
SHA-256: d67a026d817190280458ec276654b4f400d805d71563cd51c24370e474e702ff
font_01_sfnt_off0000e535.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE535 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fd47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD47 17612 bytes
SHA-256: bba9918cd70366540442252abeadd24df94ef57e1e57e8e70b95eb418d2340df