Malicious PDF — malware analysis report

Static analysis result for SHA-256 35c1a9ba91ec8dc4…

MALICIOUS

PDF

87.2 KB Created: 2021-07-02 07:18:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 1cb1f832caa327173853a488174d799d SHA-1: 01517561d5797eb95ea06c530d3e9b2f7d008767 SHA-256: 35c1a9ba91ec8dc47e84ec830a31f0fed5badedf607505ffceccd57b6bce8761
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. Analysis reveals a link farm structure pointing to numerous domains, many of which appear to be compromised or disposable. This suggests the PDF is designed to lure users to malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://accuratesearch.com/userfiles/file/34758376332.pdf In PDF document text
    • https://topinsolventa.ro/userfiles/file/pidofesapegagari.pdfIn PDF document text
    • https://anfauglir.com/images/file/zupavesopaje.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/c43pkaksn42butn87bujmd6phf/xobawusekodo.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/1608fdf6ece3f4---84149605530.pdfIn PDF document text
    • http://myphamlulanjina.com/upload/files/47143802527.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/batemareradupenex.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1608078042d965---nogexeki.pdfIn PDF document text
    • https://archltginc.com/wp-content/plugins/super-forms/uploads/php/files/d8d4d2f085da9e93d2185dd246ba6dc4/bejak.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/16096190e69276---64102051476.pdfIn PDF document text
    • http://ghioroiu.ro/sites/default/files/file/35337674305.pdfIn PDF document text
    • https://olympicwroclaw.pl/zdjecia/fck/file/13219594992.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/67ea03ce18f6375ccfaaf1835f423607/liwedulejikomi.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/477f647acdd29e10a50e00b057da5370/37499878521.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/ngj1r10v8pg1qumlfbhm7brsv0/tozedinitegogosew.pdfIn PDF document text
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/a1eec46fd69b786b75ad2eba8859bb61/72714373477.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608d9e533aad5---bubupozi.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/c5b33e839c8383afd7e55e0e797741c1/vumipibulamu.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/9fed737e79a761eb0d3b3980be60f9f4/puvugob.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/ad3db8ab20bc9e5c7718f77aff43af5a/63509322057.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/a4b32ad81088f21cf008dde5f7054962/xulifatol.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/93214154f4f416a8aadd14f65bdb30fd/rokibazijal.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/16082c6320a5ec---91810209655.pdfIn PDF document text
    • http://coreaad.com/DreamDataUpload/file/13052451342.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2415e296d4---3592149034.pdfIn PDF document text
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/vufuzokutevamodivafemug.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/tijakoxoduken.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=rest+and+relaxation+meaningPDF 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_off0000f462.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF462 16400 bytes
SHA-256: 0ac9ef6ce4f90f27c6a71f7772de47eb436b3afd91ed9631a3d2c0792e68e9fc
font_01_sfnt_off00011ece.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ECE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000136e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136E5 10740 bytes
SHA-256: 188c1a0348cf8e7a45c85fb3e26172d15e7add243b8760816863e2f59d44acc5