Malicious PDF — malware analysis report

Static analysis result for SHA-256 91be08d76c6ca0c1…

MALICIOUS

PDF

85.3 KB Created: 2021-09-18 19:52:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3923e8e33e529906675de436cfde2b97 SHA-1: 56f12f5f797a49476325ca07e31f9d4e6a438d74 SHA-256: 91be08d76c6ca0c1166fc009b7202112c92880f648e20e3d0e1812c46889ab77
74 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, supported by heuristics identifying a link farm on disposable domains. The document contains numerous embedded URLs pointing to PDF files hosted on these domains, suggesting a phishing or scam attempt to trick users into downloading further malicious content. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://pes.edu.mn/ckfinder/userfiles/files/nizobefefoxovibuge.pdf In PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/87392863267.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/40518050024.pdfIn PDF document text
    • http://autowagon.it/userfiles/files/wewutalanamomar.pdfIn PDF document text
    • http://xn--zb0bw3kv4s8mn.com/upload/fckeditor/file/budojafepaxaxezidap.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/91212634934.pdfIn PDF document text
    • http://hillsclinic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/58220038798.pdfIn PDF document text
    • http://honghuibio.com/d/files/63078450395.pdfIn PDF document text
    • https://marblobathware.com/app/webroot/img/files/mujefufijexubososikeraza.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/federepatalejoxade.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/goxanopo.pdfIn PDF document text
    • https://theptaynam.vn/upload/files/92384271932.pdfIn PDF document text
    • https://chennothinterios.com/uploads/file/10374591422.pdfIn PDF document text
    • https://datatalk.ilvzhou.com/upload/files/2021/09/202109092319351980.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16145be93c3988---dexuxevaferiza.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/161307674a1082---nevazumufop.pdfIn PDF document text
    • http://fornacedelia.it/userfiles/files/14932299806.pdfIn PDF document text
    • http://snailgame.ru/upload/files/20210914171445.pdfIn PDF document text
    • http://elma1.ru/!upload/files/pizolobejopineravejakidev.pdfIn PDF document text
    • http://gzlmjx.com/data/home/bxu2343160066/htdocs/uploadfile/files/67670219811.pdfIn PDF document text
    • https://www.rosebankprimary.co.za/inc/ckfinder/userfiles/files/gojawitodikuxafasu.pdfIn PDF document text
    • https://its-bulgaria.bg/files/file/bomeduroneb.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109111549151240.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=mod+menu+apk+download+among+usPDF 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_off0000e624.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE624 19024 bytes
SHA-256: 9b23c2fbc2542fe57ed7e4e855ad0fef54a4ce028a45d1e7f82e4303533eddc6
font_01_sfnt_off00011721.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11721 10716 bytes
SHA-256: a06f5d955a4505652512ea38355f0f7bf7e8c4fb671095d09c9048d194b25ed6
font_02_sfnt_off00012f99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1