Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1b6cc8b33f38888…

MALICIOUS

PDF

96.2 KB Created: 2021-06-28 05:31:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 7ab037e3f63f70d035d8034e7c409f56 SHA-1: 6711fce215c9d2821b4f5bd060c1eff864d59577 SHA-256: a1b6cc8b33f38888cf8e104383afaca54a14e39a06ca67c3140d837aa205f98c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links pointing to compromised WordPress sites, suggesting a link farm used for distributing further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the presence of numerous external links and the nature of the heuristics suggest this PDF is part of a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9918

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://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8ccab4e8c9---59854763833.pdf In PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607dae257a535---sukerafazuvufukede.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9cabe0f49---lukatixekukogu.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/0lhup204k1ovs1bt6l3c4f21v7/sowalajitimuvema.pdfIn PDF document text
    • http://ptairsupply.com/userfiles/file/88761848898.pdfIn PDF document text
    • http://krukewittfarms.com/userfiles/file/tosafekijodomid.pdfIn PDF document text
    • http://energo-market.ru/sadm_files/42399423232.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1609e92665dbd4---99570238335.pdfIn PDF document text
    • http://praconsulgroup.ru/pict/file/birosav.pdfIn PDF document text
    • http://asianaccounting.com/admin/fckeditor/userfiles/file/64159773039.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/japs0cre72rv2n0tbctjr0cdep/57443513542.pdfIn PDF document text
    • http://bagumul.com/file_upload/spaw_upload/file/20210524004007.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/160832ddfdc177---zenopavi.pdfIn PDF document text
    • https://alkalacarservice.com/public_html/userfiles/file/mobufinabu.pdfIn PDF document text
    • http://thedreams.cz/files/zuratojofepeb.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//76171702820.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608af46846ca0---25237799732.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16094867daaec4---ranogesojurijepuw.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160837472ee7c5---76204417745.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/c465ead867f773fcebffe78833bcdd55/xenojidawitamotuza.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6395b90edf---91029097220.pdfIn PDF document text
    • https://banderlogclub.ru/Files/file/81066252497.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160956d1c2e8ef---56441998584.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cf5a538452---fasilibamunirojumananokov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=walmart+pre+employment+test+questions+answersPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fd3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD3E 10852 bytes
SHA-256: c47d1aba82587f7bffe28cb19102f081d017e8cf3d5cfdda3ae45622f0a06ff4
font_01_sfnt_off00011651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11651 16164 bytes
SHA-256: 3ebd486235ab6c407a74d98ab9e1cf09d7661342c8c98090703f1c8ee3396579
font_02_sfnt_off00012bbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BBC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off000143ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x143CE 18396 bytes
SHA-256: 74d6993a0c4ee2e30fa0f1482f537aae1d6705144b5ed4377b9e04b1ee5ef85c