Malicious PDF — malware analysis report

Static analysis result for SHA-256 7998da36a40f6dc8…

MALICIOUS

PDF

72.7 KB Created: 2021-08-28 10:24:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 82a958849916b5797c7d07d6892bf7fa SHA-1: 0a2c202a9cd98dd0dee242bda7b3010f3286ca6a SHA-256: 7998da36a40f6dc86515cfc18e7d2d71f03ac8281dc223a8749a66baba0b9718
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several pointing to compromised CMS upload directories, indicating a link farm designed to redirect users to potentially malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://huntic.ru/uplcv?utm_term=case+study+based+questions+class+12+maths+pdf PDF link annotation
    • http://prosquash.by/data/molusezokefemotil.pdfIn PDF document text
    • http://csc021.com/userfiles/file/20210621061238_zrub4n.pdfIn PDF document text
    • http://dnepropress.net/files/file/regaxap.pdfIn PDF document text
    • http://iworking.vn/uploads/files/teretejixizosukonelibap.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/tumedoxukoliraj.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/lefedelomasawad.pdfIn PDF document text
    • http://stadtbild-intervention.de/Quansis/ckfinder/userfiles/files/zepenirigokasogigifezuxa.pdfIn PDF document text
    • http://wumag.pl/userfiles/file/54096789268.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/ngc5863e5nlbsnco893fbl4u09/felogubibafimipizezixegom.pdfIn PDF document text
    • https://infotechloyalty.com/bot/ckfinder/uf/files/65528266140.pdfIn PDF document text
    • http://capmar.eu/userfiles/file/52967540087.pdfIn PDF document text
    • http://porpora.biz/imagenes/imagenes_contenidos///togopitizovuzarimotejule.pdfIn PDF document text
    • http://globalroomplus.com/bot/ckfinder/uf/files/9218155979.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/vjvp11601tv166pg2ei1itfnhj/8602288840.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/7ebd1b637d846dd007986eeaf2dc0436/kivubapej.pdfIn PDF document text
    • http://centrlita.ru/archive/image/file/25263142129.pdfIn PDF document text
    • http://anaminfo.com/attachfile/file/72074286488.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ab58c30ba55---garukobupatikadi.pdfIn PDF document text
    • http://chothuexehochiminh.com/userfiles/file/74789237426.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210427221249183.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/zasevejipogumukabufir.pdfIn PDF document text
    • http://designbyjoseph.com/uploads/File/62547695806.pdfIn PDF document text
    • https://www.thc.gda.pl/ckfinder/userfiles/files/52252600948.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_off0000b9b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d1c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1C6 15608 bytes
SHA-256: d33cd4aeeb10d2312aa699a3a39632d7b52755425a39baa664e513f2f888a894
font_02_sfnt_off0000f98b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF98B 11488 bytes
SHA-256: 2378234809d2514fdf87fc94118f0112182be9d2ad40b43c088dd38e44526b76