Malicious PDF — malware analysis report

Static analysis result for SHA-256 39fb1eb31e693c97…

MALICIOUS

PDF

78.7 KB Created: 2021-09-14 16:55:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f1c38a79d78c75d1a42f8dc2d51cd215 SHA-1: 8c63881905866630d086e43c9184900d45597603 SHA-256: 39fb1eb31e693c97d12141bcec3b1585d55cc31892fff5bc0d60b76b25c6d1ab
164 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS upload directories, suggesting a link farm designed to distribute malicious files. The presence of a 'download' button lure and a high ML classifier score further support malicious intent. ClamAV detection confirms this assessment, identifying the file as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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.
  • 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 https://archism.ru/uplcv?utm_term=download+gta+5+apk+data PDF link annotation
    • https://ashleymongolia.mn/uploads/files/zularesofipabiwi.pdfIn PDF document text
    • https://zlataraburmevuckovic.com/files/kafakajatun.pdfIn PDF document text
    • http://gloria-eurex.com/images/blog/file/besajukusidomelenapifa.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613274d9af33c---84564988740.pdfIn PDF document text
    • http://firmen-bekleidung.at/userfiles/file/lejowipibu.pdfIn PDF document text
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613237cc3da40---nekatotukuxamum.pdfIn PDF document text
    • http://www.rodnolespropertymanagement.com/siteuploads/editorimg/file/39544548618.pdfIn PDF document text
    • https://cingenito.ca/upload/editor/file/13324677368.pdfIn PDF document text
    • http://sysquare.com/UserFiles/files/gapajumedejuwewigados.pdfIn PDF document text
    • https://cs168.tw/upfiles/editor/files/fewete.pdfIn PDF document text
    • http://falconltd.pl/cache/file/48981308811.pdfIn PDF document text
    • http://spokoino.ru/i/upload/files/20304525861.pdfIn PDF document text
    • https://kenhquangcao.vn/uploads/files/xosipigixudavite.pdfIn PDF document text
    • http://zonweringbelgie.eu/ckfinder/userfiles/files/jezopuniwusedigokutepu.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/xukipewo.pdfIn PDF document text
    • http://fusiongrup.ro/userfiles/file/53038605398.pdfIn PDF document text
    • http://kamennykoberec.eu/editor_uploads/system/files/6594643693.pdfIn PDF document text
    • https://actorconseil.com/files/file/49807067975.pdfIn PDF document text
    • https://digitaldaya.com/imagenes/file/37960481987.pdfIn PDF document text
    • http://szerecsen.hu/editor_up/1296852754.pdfIn PDF document text
    • http://alimentosldm.com/userfiles/file/5870085388.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/161381e67481f7---96139625543.pdfIn PDF document text
    • http://letsbelegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/64001112132.pdfIn PDF document text
    • http://www.mearesandassociatesllc.com/siteuploads/editorimg/file/jomawejatude.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/fkouehmkl6tjd33kbkit5uufml/60770896085.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161350ac2112df---70421303856.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_off0000c5cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5CD 21524 bytes
SHA-256: f2554a4ad94d6f91921d8d707c842934b87728933a275ae599692502e647ba57
font_01_sfnt_off0000fdc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000115dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115DC 10388 bytes
SHA-256: 4907bad853516302e42355db6b6c48847d3986a8ce3b8b2de40b9dd318a35967