Malicious PDF — malware analysis report

Static analysis result for SHA-256 4186f5428a6551de…

MALICIOUS

PDF

93.6 KB Created: 2021-07-04 04:55:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 1a9bef25a9e1c162e704b5427224bef5 SHA-1: de1d2f702b5a76cf84ccdfa7f02ae26f5cbcbee7 SHA-256: 4186f5428a6551de2653b02b9a2996ffeec954b0878410ce9bbef57246e61fe3
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites and acting as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or directing users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://abimobiliare.pl/pliki/File/pepejebifudajabu.pdf In PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609006a208e71---73147950504.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adeb7d70f8a---zemusovivoniva.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609455ac9837b---zutibudimomisidusewetorak.pdfIn PDF document text
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/7855664036.pdfIn PDF document text
    • https://pathakpharma.in/singhania/downloads/file/lajoxodakiwafoxonizebuxox.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/9378728838.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/56b8ff2bdb9ec0276c34f4e8d5c493dc/96860442435.pdfIn PDF document text
    • https://hitourkorea.com/FileData/ckfinder/files/20210613_3F8DFCE324BA818E.pdfIn PDF document text
    • http://contextuae.com/resimler/files/21327507164.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/ff92d28bc2a7311f064c50439ad1579f/gurexutabip.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb48882783---jodepujemu.pdfIn PDF document text
    • https://palcev.ru/userfiles/file/20561962396.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606d38b9bb3ce---5838550535.pdfIn PDF document text
    • https://leo.tw/upload/ckeditor/files/wuwenemumedukivebikudum.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/73552622161.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/3j3clsvf097vvriqqo6srjfh4b/votaz.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/b8ae382a6f8a2e19e7b3a212a31cc946/rusopijuwelotigigo.pdfIn PDF document text
    • https://almondzwealth.com/administrator/imagetemp/file/gafitudatogunoboj.pdfIn PDF document text
    • http://charivne.info/images/file/48547358338.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=iq+average+for+13+year+oldPDF 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_off000109f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012207.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12207 17592 bytes
SHA-256: cac48a2b54782b4c0f7152b20af00a41801ecf49ab2c39d0acc3bfa50dae9b18
font_02_sfnt_off0001506e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1506E 10568 bytes
SHA-256: 430a0baec0ab86eee085c4207154d8698ef1faa44164d197e4d13e7c284f6477