Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ac991e797b97443…

MALICIOUS

PDF

80.9 KB Created: 2021-09-17 18:14:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b3a459d5b7dce84d4c94bc814783d75a SHA-1: e6ad8549717f5bbea717df2f1b2b27309a9e93ee SHA-256: 7ac991e797b974431b8791bbe08224806f167d1056dfeccf651e9e427d85041f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URI heuristics further supports the attack pattern of luring users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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=lenguaje+maquina+pdf PDF link annotation
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/bj0fsg0dfp5uf0lujcp66cnbpv/50347709844.pdfIn PDF document text
    • http://www.libroparlatolions.it/backoffice/ckfinder/userfiles/files/67936269664.pdfIn PDF document text
    • http://murzilka.biz/images/uploads/file/55520854697.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16135d07bb2c5d---foligafefi.pdfIn PDF document text
    • http://falerisztika.hu/tmp/mugimadu.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/1fd28d3a7aef1e35463f94fec8e20012/fefuw.pdfIn PDF document text
    • https://ratosatu.com/contents/files/90672103310.pdfIn PDF document text
    • https://bluza-shop.ru/content/File/pusokez.pdfIn PDF document text
    • https://macauroommate.com/ckfinder/userfiles/files/wiwasi.pdfIn PDF document text
    • http://massvt.sk/editor_uploads/system/files/26998775739.pdfIn PDF document text
    • http://123flower.doweb.kr/upload/files/mafikidunutufovet.pdfIn PDF document text
    • https://sabagdasarov.ru/upload/file/fedupibojetik.pdfIn PDF document text
    • http://dlastudenta.org/Upload/file/92126475507.pdfIn PDF document text
    • http://miroslaws.com/ckfinder/userfiles/files/2476125600.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/r7e3bmbj2dpi7qbp13u4f6ahuh/vukiwewubutefovebagug.pdfIn PDF document text
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/jexupilonixa.pdfIn PDF document text
    • http://location-venise.com/italie_documents/files/66418815807.pdfIn PDF document text
    • https://roshnaai.com/ckfinder/userfiles/files/62986961618.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/wuvixujagewijotatika.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/venigisodizew.pdfIn PDF document text
    • http://denetimmusavirlik.com/userfiles/file/walatixaw.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/6824946512.pdfIn PDF document text
    • http://nomorecpapmachine.com/userfiles/files/15499697211.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_off0000d9cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f1de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DE 17756 bytes
SHA-256: 1ffbdad02a41f5c8a56c1684a63a9f06b67e5d6a5409120d0f72df4aa7772494
font_02_sfnt_off00011ea8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EA8 10640 bytes
SHA-256: 4695c9bd568acc2ce1078c8f0f9ef4b73359ab49e743c7b6e96de567ed7394cd