Malicious PDF — malware analysis report

Static analysis result for SHA-256 3fc06253fb6f9585…

MALICIOUS

PDF

83.3 KB Created: 2021-09-19 23:48:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: cf5135801a7f42a139afc1844232581d SHA-1: 3fd670256d3bc3c0c351b09526f1d4886f139b6e SHA-256: 3fc06253fb6f9585026175ae7ccb4ac483ba5010d9d97e74e9a036158c8f4610
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to compromised WordPress sites and other disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://chcial.ru/uplcv?utm_term=se+traba+youtube+en+android PDF link annotation
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161370ea923685---29555142993.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/4rkhl4d9bb42qecjkh5b46a2s6/kexorotinabibagutopeb.pdfIn PDF document text
    • https://www.karelo.com/uploads/File/kawajuk.pdfIn PDF document text
    • http://demirlermetal.com/resimler/files/28672500578.pdfIn PDF document text
    • http://thietbikhachsanvinhhung1.com/upload/files/80077288476.pdfIn PDF document text
    • http://wingmanplanningdemo.com/userfiles/files/tazukof.pdfIn PDF document text
    • https://miet.hu/kepek/83483190445.pdfIn PDF document text
    • http://studio5r.com/userfiles/files/63130034125.pdfIn PDF document text
    • http://bayanairag.com/uploads/userfiles/files/fefakabojesagutezapob.pdfIn PDF document text
    • http://dailygameresult.com/editor/UserFiles2/files/92985324000.pdfIn PDF document text
    • https://quangtriasianwindow.com/uploads/image/files/74770002807.pdfIn PDF document text
    • http://abwmountvernon.com/uploads/files/rediri.pdfIn PDF document text
    • http://mega-stainlesssteel.com/uploads/image/files/99851531859.pdfIn PDF document text
    • https://a-metal.e-giant.net/archive/file/files/17681710815.pdfIn PDF document text
    • http://www.photonics-science.com/ckfinder/userfiles/files/nupavekuda.pdfIn PDF document text
    • http://keletunderground.hu/images/uploaded_pics/file/36453470449.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/jepimimo.pdfIn PDF document text
    • http://muszempilla.com/files/file/totajuti.pdfIn PDF document text
    • http://baovethanglongmb.com/upload/files/87316606945.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/merarijapemaxeti.pdfIn PDF document text
    • https://cissud.eu/uploads/ck_editor/files/wapur.pdfIn PDF document text
    • https://durimawar.com/contents/files/12837094210.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161479a22bf2f8---zefevupabuvud.pdfIn PDF document text
    • https://didacostruzioni.it/userfiles/file/jokozavukawisite.pdfIn PDF document text
    • 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_off0000de67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE67 19392 bytes
SHA-256: a1eeac55bb39ae7345a2d00b4f53403910633b9bc4a3048ee18070c25c9528b6
font_01_sfnt_off00010fd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FD8 10456 bytes
SHA-256: 43a05431654671ea0a0510b37c138f0efa7513de0b7db8ee15737d87957ffd84
font_02_sfnt_off000127b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127B5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1