Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b4c231752d16467…

MALICIOUS

PDF

93.8 KB Created: 2021-09-07 17:21:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 57cddb12261ed69dcc123e0392cd1753 SHA-1: 61e30ad06afb424f0d24d887374306e5a990638d SHA-256: 4b4c231752d16467e935004fb9929863955bc5741bef45fdeaca5b73bdf5b10a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains a large number of embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of these links indicates an attempt to facilitate phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://krisoc.ru/uplcv?utm_term=administra%C3%A7%C3%A3o+geral+e+p%C3%BAblica+para+concursos+pdf+download PDF link annotation
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b7a55e0cdc---falame.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eff877c502---62041974588.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611412fbdac00---vovovatojajezulibabet.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6b2379488---80769004955.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/a4aafcacc754758e356db996d1dad8df/dudoxusolubovawis.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/pp7hv57lb05h1qncpgbg64h735/fewopubefalolevekovosupev.pdfIn PDF document text
    • https://pmms-online.com/assets/file/katenajuxodelapeg.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/tonilutevozile.pdfIn PDF document text
    • https://naveenent.com/administrator/imagetemp/file/vuzarefumanuxuzadu.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/afebd21119ab84afb5ce1afc18893b04/lijajazixux.pdfIn PDF document text
    • http://kvrhousing.com/uploads/88304680017.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/29dcc3d2736c40d7c0aad6a82b92dda6/wugebula.pdfIn PDF document text
    • http://goodslib.com/userfiles/files/4538038094.pdfIn PDF document text
    • https://genericdiabeticteststrips.com/userfiles/files/modixopopafot.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/201b7pqlh6hll0l1lum0o361ki/41079458460.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cedf66b1f05---17930051227.pdfIn PDF document text
    • http://www.aluvascientific.com/UserFiles/file/zuxawiguvatiduxuneg.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094177a64684---sijajelasujekeranubi.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/f9df02bfc5666ca5d56bb4ce481ace3a/1448012081.pdfIn PDF document text
    • http://hkacca.com/userfiles/1614358553.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021070813464764.pdfIn PDF document text
    • https://grupo-kayros.com/userfiles/file/sosisam.pdfIn PDF document text
    • https://teenvolunteerhouston.org/wp-content/plugins/super-forms/uploads/php/files/17b1c36309f5dc32c1ddea3933c22b22/60517264721.pdfIn PDF document text
    • https://supermagnum-bg.com/userfiles/file/9214740371.pdfIn PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/gelatakul.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_off0000fd84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD84 11852 bytes
SHA-256: cf5a4d685cd304ab5ae8c374bab30999e7f19522893afd8659a70c6f9a97b80e
font_01_sfnt_off0001189d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1189D 21708 bytes
SHA-256: 474669f250033bec24f1a281b5aabda07c768fb63fad73689a2928df6234f5a5
font_02_sfnt_off00014e96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14E96 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1