Malicious PDF — malware analysis report

Static analysis result for SHA-256 85c10d9f4e1668db…

MALICIOUS

PDF

81.8 KB Created: 2021-09-17 18:25:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0c7460d1a6d05a676ef07c67da275e9e SHA-1: c477b8249c43f26f3306a5a2115a3f90c7bc7b01 SHA-256: 85c10d9f4e1668dbfa4a27d73b9baccbd492b53115c3219362d3dfc8dd2d45da
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs hosted on various domains, many of which are flagged as potentially suspicious or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document's structure and the nature of the URLs suggest it's designed to lure users into clicking through to compromised or malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://styrexon.cz/userfiles/file/kitisowevapisevufitovup.pdf In PDF document text
    • http://ddaengshop.com/ckupload/files/wudatajawinagopobuzabivu.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/93991017189.pdfIn PDF document text
    • https://epagneuls-bretons.fr/caningest/images/file/92782552171.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/sujisemupasi.pdfIn PDF document text
    • http://rent-lease-no1.com/userfiles/file/20210917213725.pdfIn PDF document text
    • http://virtuozi.ru/sites/all/sites/virtuozi.ru/files/62157071034.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b903337320---gejajo.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/676ff9d9e3081b532f008f6495eb0f1b/17291098544.pdfIn PDF document text
    • https://silverlabpupsforsale.com/userfiles/files/42845423243.pdfIn PDF document text
    • https://marblo.ph/app/webroot/img/files/fotetibopatibusa.pdfIn PDF document text
    • http://studiotecnicodambra.eu/userfiles/files/zizagakuwutelulu.pdfIn PDF document text
    • http://ahzgbh.news-read.com/upload/files/17850205604.pdfIn PDF document text
    • https://cafesca.mx/ckfinder/userfiles/files/gumorijifixugusudekezew.pdfIn PDF document text
    • http://tecksco.com/upload/files/8400638709.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb331e92da---83348504756.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/16139bcd425e73---64755420809.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/38399233791.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/gagefokozowawasazaviluba.pdfIn PDF document text
    • https://www.twibiotech.com/plugin/ce1/ckfinder/userfiles/files/29087089462.pdfIn PDF document text
    • http://oskarmak.com/userfiles/file/44112217858.pdfIn PDF document text
    • https://twinslock.com/locktactyuma/userfiles/file/59987600750.pdfIn PDF document text
    • https://quangcaonoithatgiahung.com/admin/webroot/upload/image/files/vavapovujodefikidil.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=hyperfocal+pro+appPDF 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_off0000dfe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFE1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F3 16720 bytes
SHA-256: cb60e1f9a19398a5b6d1f7127ffa5f187b131186ab8506ac150ae9aa01080aa9
font_02_sfnt_off0001237b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1237B 10116 bytes
SHA-256: e144c7c352ec15c6577e42254832ea5de9937a21e2be3ef90c2a223b6f49f62a