Malicious PDF — malware analysis report

Static analysis result for SHA-256 6691d781c6d47cff…

MALICIOUS

PDF

81.3 KB Created: 2021-09-16 14:12:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 067c7eafdcc8dc7b7f4fd71330220f5c SHA-1: 9de4e3e577ef67e865c3e7609d2a4b88c6579d5a SHA-256: 6691d781c6d47cfff3fb12e9adcc755e1558624a8c4bddd8447ee28a1196afa4
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm containing numerous URLs hosted on potentially compromised or disposable domains, such as synerhu.ru and amezdigital.com. The embedded URLs are designed to redirect users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://synerhu.ru/uplcv?utm_term=play+store+app+not+download PDF link annotation
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/851d35237c26a7a7f19253787f9125c9/xupegegowekimot.pdfIn PDF document text
    • http://turskazka.ru/ckfinder/userfiles/files/98014400479.pdfIn PDF document text
    • https://allegypttours.net/userfiles/files/mapobugaro.pdfIn PDF document text
    • https://33mobility.net/uploads/files/29535167547.pdfIn PDF document text
    • http://avon-bratislava.sk/files/files/nivefigojixilorubir.pdfIn PDF document text
    • http://www.miyadenthai.com/image/upload/File/58388156893.pdfIn PDF document text
    • https://regionalhealthprogramsww.com/images/file/jumiji.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/b747c1f6049258ded6e261fc196d76aa/14684828885.pdfIn PDF document text
    • http://hrt-foto.hu/_user/file/88498605536.pdfIn PDF document text
    • https://joebalogh.ro/imagini_ws/48562531258.pdfIn PDF document text
    • https://z87992961.com/upload/files/20210905021025.pdfIn PDF document text
    • https://istanajp.com/contents/files/11962839275.pdfIn PDF document text
    • http://gzlmjx.com/data/home/bxu2343160066/htdocs/uploadfile/files/vejipupudaroxafoxuxokon.pdfIn PDF document text
    • http://herve-coiffure.ci/files/68726484354.pdfIn PDF document text
    • http://interel-rus.ru/test/sites/default/files/file/xititeb.pdfIn PDF document text
    • https://bhavanarayanaswamy.org/userfiles/file/36089311217.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613817671f448---rufodudetabiloz.pdfIn PDF document text
    • http://195exim.com/datas/files/55944008313.pdfIn PDF document text
    • https://greenlakepaint.com/ckfinder/userfiles/files/zixijikarowunu.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcdb799600---vugetizuvonow.pdfIn PDF document text
    • http://kmkonsult.cz/userfiles/file/70423741246.pdfIn PDF document text
    • http://signauction.net/userfiles/file/39375849643.pdfIn PDF document text
    • http://connect-senior.ch/uploades/userfiles/file/xosumafexubopen.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613caa794e665---46881881121.pdfIn PDF document text
    • https://vkgnassociates.com/dayafter/uploadimages/newsimages/file/74406033667.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_off0000d9b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9B7 10492 bytes
SHA-256: 807cbf3337587e3dc5f7f80a8e75309de29f3999a94f4b7a076d3c37fe9c4a33
font_01_sfnt_off0000f1d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D6 17900 bytes
SHA-256: 235457c58a4491d974a0d841649d6c8d037fd448fad7b9d33e52a5f4bef0892b
font_02_sfnt_off00011fa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1