Malicious PDF — malware analysis report

Static analysis result for SHA-256 3091509d4630aeb7…

MALICIOUS

PDF

82.9 KB Created: 2021-09-16 08:10:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b92b9b9fa7d141e9ff16064546e7623d SHA-1: 0dfdb16959b7dd187aef32ea3d145b9652234fff SHA-256: 3091509d4630aeb79edf4f4de01ce9f38829995e0a9266aafe22df2b77a29174
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The sample also exhibits characteristics of a link farm, with numerous URLs pointing to compromised WordPress upload storage and disposable hosting. These elements suggest the PDF is designed to lure users to malicious sites, likely for phishing or to download further malware. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614112a6da282---bapikizenanikilorotabube.pdf In PDF document text
    • http://solmoda.it/userfiles/files/8599050749.pdfIn PDF document text
    • https://lapakunited.com/contents/files/6525261135.pdfIn PDF document text
    • http://carnow.jp/js/upload/files/ludomebipun.pdfIn PDF document text
    • https://khangle.vn/uploads/images/files/37859722761.pdfIn PDF document text
    • http://rc-mst.com/mst/_upload/files/43960820621.pdfIn PDF document text
    • http://w-w.cn/isee/pfm/cms/uploadfile/fck/file/49804065371.pdfIn PDF document text
    • http://dae-young.kr/upload/fckeditor/file/muwunupivujovoguwid.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210910155109.pdfIn PDF document text
    • https://cubic.is/userfiles/file/tobotawosep.pdfIn PDF document text
    • http://klwas.org/userfiles/images/file/fofavaxumasefo.pdfIn PDF document text
    • https://encoyun.com/calisma2/files/uploads/99528274938.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613455066e9d0---30192865348.pdfIn PDF document text
    • http://n3ss.ro/ckfinder/userfiles/files/datiritodefixixijutima.pdfIn PDF document text
    • http://aesg2edcv.handylover.com/upload/files/38220447087.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1613afb4ce6a0a---22044815864.pdfIn PDF document text
    • http://www.greenlakecruises.com/ckfinder/userfiles/files/45716507849.pdfIn PDF document text
    • http://beijingteye.com/upload/files/20045121030.pdfIn PDF document text
    • https://milorem-service.ru/userfiles/file/lawagurobefobikidajugaz.pdfIn PDF document text
    • https://digitaldaya.com/imagenes/file/60025363242.pdfIn PDF document text
    • http://ministerium.pt/files/2705217420.pdfIn PDF document text
    • https://franchise-vietnam.com/app/webroot/img/files/bafelukikidudovekoduja.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/161405fbddcb80---92202381685.pdfIn PDF document text
    • http://88cpap.com/userfiles/files/pokukarosirugizafazuda.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=alcatel+link+app+old+versionPDF 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_off0000de1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE1A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f62c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF62C 18144 bytes
SHA-256: a82a61e3c4d684557bd0e6cb8d4ba3ce954b561d901343a5f756991cc1febd3d
font_02_sfnt_off000125d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125D9 10644 bytes
SHA-256: 3c251d0a2e85446f412d0a2bfbe8b5454dd3c8c3c0f343299e520598af027bf9