Malicious PDF — malware analysis report

Static analysis result for SHA-256 581e8dbeb5c1660b…

MALICIOUS

PDF

88.4 KB Created: 2021-06-29 12:19:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: dd8278cfb07cc21714619ab7139f2ccb SHA-1: 2d2c3d14e122c1cb0ae15f3fd827fa8dbe0f100b SHA-256: 581e8dbeb5c1660bb88741bc7247ec4b05ff870500e7f8a7d246af73e7caa34e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, presenting numerous URLs that point to compromised CMS uploads and disposable hosting, likely to distribute further malware or phish for information. The presence of external URIs and link farm characteristics strongly suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/fcm2sfu6e7kss5carugp91ehn5/44403033178.pdf In PDF document text
    • https://anfauglir.com/images/file/53804569670.pdfIn PDF document text
    • http://shssailors1969.com/clients/3/36/366f78b21138e0f8005dfe6cc5e09e30/File/49395385813.pdfIn PDF document text
    • https://texigo.tw/upfile/files/2021/06/25/52512483595.pdfIn PDF document text
    • https://vnsteeldetailing.com/UserFiles/files/zapuzegetulojobib.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/083185bcf682079e64f077d938615ced/gesogulututonan.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/ffcc00964cea282d6b44fb9a31751062/mixorotow.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16083cc65845c3---menofo.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a1a8036c5c6---lobeximirudifevuvinito.pdfIn PDF document text
    • https://samarthanamparisara.org/apadmin/uploads/userfiles/files/97797476375.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/6a6jtu4jk7di3ijsa585p26k35/7583597583.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607e80d37e254---59933745188.pdfIn PDF document text
    • https://apoiotelecom.com/imagens/img_fckeditor/file/fukasugibebaluzefozoz.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/92672344398.pdfIn PDF document text
    • https://boyanbolyarski.com/userfiles/file/ximuvebu.pdfIn PDF document text
    • https://akita-inu.lv/www/files/files/83620688722.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/3m93tmu9dniqjhu0qrf0bt3es9/65342611320.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160986de33fdd3---10188732142.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/d9bd8b5b7dbb2d4263b214c12ec87cc9/punefopozudavulenunu.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160948942a1804---setimegiwimosokobewanixe.pdfIn PDF document text
    • https://drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16085dac00fe53---nepojapuzuzububokekafiwek.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a5707ce2e87---wuxuxopusurirowima.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/0953ebafe91514258694f2628e3bdd91/piluzu.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/mmuaa1gcq8443cbajs00m73cq1/76945559752.pdfIn PDF document text
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/fcf70468a5a36fae4ddbf7a4589bd7ca/jozexakadajubajikef.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a61f723ed86---pefawiba.pdfIn PDF document text
    • https://burstallconrad.com/editor_files/file/51262945428.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=ambling+meaning+in+englishPDF 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://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_off0000f09d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF09D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000108b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B4 10356 bytes
SHA-256: 54ae5003938a0df8f253227818ad4f3309d89c124f180ba7cea81748d68f1542
font_02_sfnt_off00011fcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FCF 20096 bytes
SHA-256: 3ee8a01f3145dfde0e08523f4b5785acc0981868ae50cf5d12bbdb750590cf32