Malicious PDF — malware analysis report

Static analysis result for SHA-256 5526ee99b5110c0d…

MALICIOUS

PDF

77.1 KB Created: 2021-09-14 07:53:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d9edd7d7436bb143e65a85bbc0db2011 SHA-1: 55d0983982c90e9f47e19317032e0903530288b5 SHA-256: 5526ee99b5110c0d61ca8def2e7801fbebc2062fc703d0a98c0a4a1392b186d8
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The presence of 'utm_term' parameters suggests an attempt at SEO poisoning or phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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=total+conquest+hack+game+download PDF link annotation
    • http://salondebellezaanamariaromero.es/ckfinder/userfiles/files/52841375840.pdfIn PDF document text
    • https://agatanorek.com/files/file/4341123521.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210914090244.pdfIn PDF document text
    • http://lezeckastenakosice.sk/upload/files/51454170644.pdfIn PDF document text
    • https://hoangphatdanang.xetnghiemadndanang.com/uploads/image/files/lafazumakazib.pdfIn PDF document text
    • http://abpjseah.news-read.com/upload/files/27333555013.pdfIn PDF document text
    • http://gorod-r.com/userfiles/file/41422584007.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/16136d43dbe20b---vatejefif.pdfIn PDF document text
    • https://malayalamfoundation.org/admin/my_files/file/dofenogogodazovafafuvegu.pdfIn PDF document text
    • http://hanasushimenifee.com/uploads/files/fisanuwojonit.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/lekepipowukuvevotekexe.pdfIn PDF document text
    • http://findusafranchise.com/files/files/tujefugaxara.pdfIn PDF document text
    • http://tjchenxing.com/filespath/files/20210904162026.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/dezuzefodewinivez.pdfIn PDF document text
    • https://alaqart.atelierleuthold.ch/userfiles/files/bafamuzagovalasubapuloxuv.pdfIn PDF document text
    • http://alocainghien.com/uploads/userfiles/file/tovikewoperutumamifa.pdfIn PDF document text
    • http://ajarnveerapong.com/UserFiles/file/loresuralozedabejom.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16136baacaf2c5---dotewozomiridonagup.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/b6ce430ce370185c9d120ba5e8bc7937/nuforixid.pdfIn PDF document text
    • http://ghefoot.com/fckeditor_userfiles/file/joxozekilakikekorevik.pdfIn PDF document text
    • http://crabandclaw.com/uploads/files/27977607737.pdfIn PDF document text
    • https://thic.net/plugin/ce1/ckfinder/userfiles/files/80005501942.pdfIn PDF document text
    • https://directorvincentchow.com/fck_filemanager_upload/file/76629460297.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_off0000c793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC793 17896 bytes
SHA-256: 6eee2b1217aff0ab46786dca0628368ed60b5da7c45513a994d6b9667777abd6
font_01_sfnt_off0000f60b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E22 11012 bytes
SHA-256: cc763eaea10c96d54d96d771f83af56582d1c422867ca83085bbb26b24500306