Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f8157907c9604b2…

MALICIOUS

PDF

86.1 KB Created: 2021-06-29 10:11:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1e4979ccbc8ff51b92a6fb980ac4dbf7 SHA-1: 2660ee7c51716b7652f50767118eba859dbcdd6c SHA-256: 3f8157907c9604b2e5d93b39f71a563ae8cd232789cf880eb1020822ec8e29dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The document contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting it functions as a link farm to distribute phishing content or further malware. The presence of external URIs and link farm characteristics strongly suggests a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://synerhu.ru/uplcv?utm_term=comptroller+and+auditor+general+2020
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089e72f62e7e---wipuzotev.pdf
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/d0a2253c17642ab7288f0e3694637bef/rigekazanuxode.pdf
    • https://contabil-fiscal.ro/mm/file/98541000622.pdf
    • http://school19-zav.ru/userfiles/file/dapalivita.pdf
    • http://j-club.eu/userfiles/file/dajalafam.pdf
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/695b8518f02730c3a9952a69842a8a2f/54212128052.pdf
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/fa1675fa7171a11873313ed461eb49a5/63469048362.pdf
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c096500d31---dopotiwufusawenojowet.pdf
    • https://anukulagrotech.com/userfiles/file/46207977176.pdf
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/zufududabijapa.pdf
    • http://tourister.kr/userfiles/file/peperotimenutazuza.pdf
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a8c557da4e3---pijesegunegeno.pdf
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/p9pjf3o8usdjl7su4avfcibotk/37969247105.pdf
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/56692b1e4076531b30c893cca0cead4c/bopanuvemezejadelusux.pdf
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/16072000ddcf62---laxidovizal.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160cae2f407598---tapisajuwu.pdf
    • http://udmvdpo.ru/images/files/43371967151.pdf
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce5d10c7eb---83468458167.pdf
    • http://abovomedia.hu/_user/file/boxipobezotu.pdf
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d9fb9bc34e---xezivokawebupenelatobomu.pdf
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/e24e74bb135b52b1053a7a7da100b5ee/xifufinozonodapireliw.pdf
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/tit0mcioje821lqa8cgjg2j572/74614485400.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160c323dd9c970---rotizijepumevo.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec39.bin
d256863a0db7720db9fa3745c4fc7a36367cb45c791dbd81c7a0a9c2c92e63ac
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC39 16820 bytes
font_01_sfnt_off00011836.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11836 16792 bytes
font_02_sfnt_off0001304d.bin
4cd4cc9ddd05bbc91c3badc6dacf734a58f43c0224d85551d941b19d5e2be275
pdf-font-stream PDF embedded font (sfnt) at offset 0x1304D 10940 bytes