Malicious PDF — malware analysis report

Static analysis result for SHA-256 528fd01312e94d76…

MALICIOUS

PDF

83.9 KB Created: 2021-09-05 20:26:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ca666e95fa8b50739b8d0e8bf215fa3a SHA-1: d2ebf6d1961baf6053217cae38a771f26b6ea249 SHA-256: 528fd01312e94d7654630035990a0128a74da2267f006253a6503ca4e38a89db
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other domains, suggesting it is used to redirect users to malicious content or phishing pages. The presence of multiple external URIs and compromised CMS upload links reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://medvor.ru/uplcv?utm_term=magmatic+differentiation+and+assimilation+pdf PDF link annotation
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092a07e797ef---zomibefovonesagewik.pdfIn PDF document text
    • https://roeveragri.ac.in/wp-content/plugins/super-forms/uploads/php/files/2b706f40f0e96bbad685aa9e05e96f8b/53199848566.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/gezunuxagaxemipapote.pdfIn PDF document text
    • https://nvsrolko.org/ckfinder/userfiles/files/24381642279.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e7c39ce574---75025514052.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/444f6aebca4393294c28082e85ea11e5/98620721228.pdfIn PDF document text
    • http://worldofpacifiers.com/editor_uploads/system/files/78367347946.pdfIn PDF document text
    • http://istrouma1971.com/clients/9/9b/9b88b062b8d6af44b28e209fcb06d7d5/File/wabegixab.pdfIn PDF document text
    • http://deauville.ru/files/file/vufitukadovadeberogux.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074b7635f209---54203976748.pdfIn PDF document text
    • https://bomberosdenavarra.com/userfiles_nexo/files/74083176755.pdfIn PDF document text
    • https://soudurelausiere.ca/upload/editor/file/6661790524.pdfIn PDF document text
    • https://immo-cjeanpaul.lu/userfiles/files/jawobupogixiz.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c2150e5fb69---77828057926.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/nkjohm2pfgkbh29f55t1me5j9b/87817087099.pdfIn PDF document text
    • http://www.accl-calibration.com/login/ckfinder/userfiles/files/20286757078.pdfIn PDF document text
    • https://yar-net.ru/userfiles/file/pigubateda.pdfIn PDF document text
    • http://4yoga.by/pics/files/gedupobufegotonemupapes.pdfIn PDF document text
    • http://bjyhyy.cn/filespath/files/20210816070846.pdfIn PDF document text
    • http://jarosi.hu/files/file/baxivurovot.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_off0000e40d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE40D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC1F 17380 bytes
SHA-256: 266adec3458c71ec86bae371b0c769819cb891e904ef16f9e99531b684b95dff
font_02_sfnt_off000128e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128E0 10956 bytes
SHA-256: 7df78f3591cf40cfc5737cc9d4bafafd437cfe20182306bb7e0626c965f0dc8a