Malicious PDF — malware analysis report

Static analysis result for SHA-256 d881507540a81228…

MALICIOUS

PDF

81.8 KB Created: 2021-09-05 09:21:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 9ed7e6e1530d40c027d39b645668be79 SHA-1: 2b69e8be38c97db646a04c1d5b034b4b0e057836 SHA-256: d881507540a812282e781ec337ceb620e1ecc048590fc58ac4274294e555fbfd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites, which is a common tactic for phishing or malware distribution. The presence of embedded URLs and the PDF structure suggest an attempt to exploit users through deceptive links, likely as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://nnkcreations.com/userfiles/file/wiwinovap.pdf In PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/v7kchs7ssg0jvvutcjn04gir18/jububifuvixemizisu.pdfIn PDF document text
    • https://norservis.cz/files/files/xiloritonipafeto.pdfIn PDF document text
    • http://3q1p.com/upload/file/210619165248970752h6ad1v5pbyfj.pdfIn PDF document text
    • https://aimara-bg.com/userfiles/file/18935786800.pdfIn PDF document text
    • http://sinorarechem.com/upload/files/74743201216.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607496413b904---loniravodezux.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607c17617da58---lesewitevasolovi.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609936b15626f---nabaj.pdfIn PDF document text
    • https://www.qlsny.com/wp-content/plugins/super-forms/uploads/php/files/34687b522263ec360a85c6c59e68f8b5/60559536831.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/0c7a05d1a3d0e777c2eac51e528198e4/dumoboninopu.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/bosusuwozaliwizumu.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/17vc3vbm533joenb8jg4bb93p1/50979363148.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c23487cffdd---pojolenisujin.pdfIn PDF document text
    • https://majubesar.net/contents//files/67789516360.pdfIn PDF document text
    • http://bancasemecanino.com/userfiles/files/donod.pdfIn PDF document text
    • http://ylgems.com/file_media/file_image/file/fanezanumosumesofarinef.pdfIn PDF document text
    • http://tauroconsulting.pl/userfiles/file/92793259377.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/160b51cfb94b037d51a13da78538c4f4/xigujesatefafokezejelup.pdfIn PDF document text
    • http://agriturismolataggiasca.eu/userfiles/files/28975553373.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/cf0gqq3jtkjel2hlf1tlirs495/18323503658.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=lilienfeld+foundations+of+epidemiology+pdfPDF link annotation
    • 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://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_off0000dd13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f52a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF52A 10912 bytes
SHA-256: dcc6e28d6f204aeac64a91802b6e8a33fed104e3b5f97ef1ee2bfd8cfe3ac788
font_02_sfnt_off00010e34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E34 17552 bytes
SHA-256: a12b1cf47bb9053ec34b888d428c3b7edf7a6bf32786c8e5b833a5071daa71bf