Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef1e5409f795c7b6…

MALICIOUS

PDF

85.5 KB Created: 2021-08-15 21:52:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8d916ed46735026dfa13d43849b168af SHA-1: 9510e26ece6767c1a59b80413c1f84f24f4dcea6 SHA-256: ef1e5409f795c7b6ddaf8d6e4f49a1d766bae90ab0222fb9ed306eaf26fcb81c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The ML classifier and ClamAV both strongly indicate this PDF is malicious. Heuristics reveal it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. The presence of numerous URLs, many hosted on compromised WordPress uploads or disposable domains, suggests an attempt to distribute malware or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://retroldn.com/userfiles/file/gazejumuwuvimi.pdf In PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/jcuc9a9vvjs7bie7349ajmnei7/96866393917.pdfIn PDF document text
    • http://thedreams.cz/files/74418552121.pdfIn PDF document text
    • https://allcreaturesinc.com/files/files/zazekesotu.pdfIn PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/16084b5056c44e---29489960925.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/3dbrjlh8caauk8vk7v37re07f1/8285321021.pdfIn PDF document text
    • http://aeronautike.com/userfiles/file/fokiwu.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cacd1da09aa---bopuwutumokuguzulol.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/eecdf1b502d052e5b9bf4e55e78172da/nubisovev.pdfIn PDF document text
    • https://protrialse.eu/files/files/kotoxuzipenisav.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/048c9de2ff61c002702a48a5e384488a/xanupasaminizezuwi.pdfIn PDF document text
    • http://kameleonhastanc.hu/files/file/desulunirizip.pdfIn PDF document text
    • https://buka.ru/sadm_files/tedenisadun.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/72457c406781e8d35c40cba2d27ffa51/pefekupuzugufuvanajese.pdfIn PDF document text
    • http://nandishoverseas.com/UserFiles/File/31851454657.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161142e0a71c5d---72059876692.pdfIn PDF document text
    • http://minhledtran.com/luutru/files/puput.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/16109b119dbcbb---vixinovugi.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/7b7e3ea2747c7796391d1abcf95fccd9/19935940964.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/5d8dce7eda9e65bb680877084f83a7bd/32715234928.pdfIn PDF document text
    • http://szolnokepul.hu/userfiles/file/zuvunubovatug.pdfIn PDF document text
    • https://botroul.be/uploads/vulanegesokeza.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/051f0c59e2370aa20ef83e2e5d2ca3ee/14741416346.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=are+zara+shorts+true+to+sizePDF 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_off0000eb37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB37 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010349.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10349 17516 bytes
SHA-256: 9842f67bc0f64b77cf339f24f5c7b01942bf4b84075e4021b84388bee18345c8
font_02_sfnt_off0001318d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1318D 10196 bytes
SHA-256: c2a7241c3a45f7d8a3eb9d1c41682f6bb767bce271dea7098b4bd9a0a86abecc