Malicious PDF — malware analysis report

Static analysis result for SHA-256 33a5ed1db1a134ef…

MALICIOUS

PDF

69.0 KB Created: 2021-09-29 12:54:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: db17d5d5524619c27bc0890d9901e75f SHA-1: b3e6f8b3b246ed50ddf28951dbb2366ebd280be9 SHA-256: 33a5ed1db1a134ef588a603073d9a4a99962a416deec4e01b076698c011be0ca
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. It also features a link farm with numerous URLs pointing to potentially compromised websites, including a specific instance on a compromised WordPress upload storage. The ClamAV detection and ML classifier further indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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=multiple+apps+open+android PDF link annotation
    • https://blogsma.com/files/tefuligilebimojefi.pdfIn PDF document text
    • http://altinay-law.com/images/file/42182300564.pdfIn PDF document text
    • http://sensitiva.fi/UserFiles/File/kukolojumase.pdfIn PDF document text
    • http://gonvvama.net/filespath/files/20210927041610.pdfIn PDF document text
    • http://basketaci.cz/UserFiles/File/26424778928.pdfIn PDF document text
    • http://lakshimi-kaatsu.com/user_data/packages/default/imgfiles/fanukuboxuvegarodirezafan.pdfIn PDF document text
    • https://smartstone.ca/userfiles/files/dunuma.pdfIn PDF document text
    • https://kristinanamaste.eu/files/75465823522.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614f1acde5fb5---78754558632.pdfIn PDF document text
    • http://tipkeo.com/js/ckfinder/userfiles/files/tizapawekisorunofofazeva.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161441259d90fb---64227214336.pdfIn PDF document text
    • http://cn-daomeng.com/upload/userfiles/files/1f6ac918060bc71e3ec9a9d5d80de89e.pdfIn PDF document text
    • http://dj-maily.com/uploads/pages/files/napiwufuf.pdfIn PDF document text
    • http://www.peretprod.ro/content-images/file/bavipadafejusebenemuvi.pdfIn PDF document text
    • http://lagrupacio.cat/file/josoruja.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/f1bb4b0d3932de918873ea52886d4f27/juzudukokepikesarige.pdfIn PDF document text
    • http://studiobaldizzone.com/userfiles/files/jepamuwegejowukelufezeki.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/68319423174.pdfIn PDF document text
    • https://doublehair.center/upload/ckfinder/files/balizonilivopux.pdfIn PDF document text
    • https://mots.alaxarxa.cat/cmsimple/images/file/12648463422.pdfIn PDF document text
    • https://melz-feu.ru/upload/72040838075.pdfIn PDF document text
    • http://podushka.by/files/files/13520094666.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_off0000b10c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB10C 10476 bytes
SHA-256: abd86a8b0077e631016f10bdb1db4abd982517dc837678a5d672f24dd1b1ec05
font_01_sfnt_off0000c8f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8F0 14812 bytes
SHA-256: 59bc493df6e30deddad8020e9d75e6696765ba057574423e552bc772bb6a7636
font_02_sfnt_off0000ee62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE62 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1