Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b558973d03bca9c…

MALICIOUS

PDF

77.0 KB Created: 2021-09-01 17:53:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: c334744866424bac7aa4ffb4c101c9f2 SHA-1: cc358c43131b20e294c332a832c69004ec398f0d SHA-256: 5b558973d03bca9cb338ccd732afb56854f56b82705a45ff942bd231ad90decd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://assytekservizi.com/userfiles/files/junokofozoxefalewexa.pdf In PDF document text
    • http://andlupa.com/userfiles/file/52729549423.pdfIn PDF document text
    • http://pro-elec.ru/ckfinder/userfiles/files/5160963258.pdfIn PDF document text
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/a37459fcef273b55ac738be16172d9ab/darofusigabemekewegi.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/065d4efa239195f619518a3339d5f6e9/sikutitedudotuka.pdfIn PDF document text
    • http://sxcec.org/userfiles/file/xiboru.pdfIn PDF document text
    • http://poslovniimenik.net/firme_data/files/1242467920.pdfIn PDF document text
    • http://ff-engineering.com/userfiles/files/vujinulobuf.pdfIn PDF document text
    • https://fibra-optica.ro/ckfinder/userfiles/files/16894166948.pdfIn PDF document text
    • https://vili-al.com/uploads/wysiwyg/files/37342530399.pdfIn PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/ijribp9sc5uva74mjelldat7i4/80382450484.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/nv3o4ikemfgiuvql3v903ls6o2/95887792598.pdfIn PDF document text
    • https://diphong.com/uploads/xinuvaradebe.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f284854d4bd---wapadut.pdfIn PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/nojg7j0gs84ocfcl4dg2kfbvnc/46708170839.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16083c5727c7c3---63851768611.pdfIn PDF document text
    • https://tckontrola.hr/files/rexutajugurubekiv.pdfIn PDF document text
    • https://j-kowalewski.pl/uploads/userfiles/files/dudolusum.pdfIn PDF document text
    • http://lmyc.net/clients/875386/File/89279123812.pdfIn PDF document text
    • http://twozonechickenlasvegas.com/uploads/files/vaxulepoledebitafole.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/vojonemipeg.pdfIn PDF document text
    • https://www.aukuras.org/ckfinder/userfiles/files/telonijovamamal.pdfIn PDF document text
    • http://dztechfin.com/upload/file///nawamagemifasutugizim.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ab146110cae---40440252749.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=the+junction+eateryPDF 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_off0000c6b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6B3 18408 bytes
SHA-256: ac0c2ac41a948df78a9ad30eb0b17d7c86202f25fb18a9a0e8c9bc8601ece73c
font_01_sfnt_off0000f689.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF689 10420 bytes
SHA-256: cb016e0444930720b5551722674e1d152fa9cfe1c8d0986da559782c454ca763
font_02_sfnt_off00010e1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1