Malicious PDF — malware analysis report

Static analysis result for SHA-256 36dc77f132c02426…

MALICIOUS

PDF

87.9 KB Created: 2021-09-17 19:22:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8f3fdc28c870a3a8eba7b5f9ff188285 SHA-1: 9b59ad34c8b3e7548485f572ae83af1ef763059d SHA-256: 36dc77f132c024260591acae3417533dccf4834725639780861002fa037a9dcf
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The presence of numerous external URIs, many pointing to disposable domains and employing UTM parameters, suggests a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving the download of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=wibr%2B+pro+apk+download PDF link annotation
    • http://jjw-led.com/userfiles/file/34803045596.pdfIn PDF document text
    • http://gsprojekt.eu/userfiles/files/48729947858.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/ditomeduv.pdfIn PDF document text
    • https://wittnebel.dk/file/3651794174.pdfIn PDF document text
    • https://larustt.com/upload/ckfinder/files/wirenumelituri.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138923201571---zonebe.pdfIn PDF document text
    • https://alpinebadmintonacademy.com/ckfinder/userfiles/files/38406695398.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/6a08c7c79ddcbcc631e75db3090a1b1c/votaratanemopimetikok.pdfIn PDF document text
    • http://bbdecontra.com/userfiles/files/49075809083.pdfIn PDF document text
    • https://sibservis.com/ckfinder/userfiles/files/9695324256.pdfIn PDF document text
    • http://kondicionery-ivanteevka.ru/upload_picture/file/86556184341.pdfIn PDF document text
    • https://brillimet.com/uploads/files/202109080248512726.pdfIn PDF document text
    • https://cherrychile.cl/cherry/uploads/contenido/files/kafevuvawubon.pdfIn PDF document text
    • http://solyaris.pro/admin/ckfinder/userfiles/files/mefaribo.pdfIn PDF document text
    • http://hoangminhsaigon.vn/@dmin/js/ckfinder/userfiles/files/xulimipaxasajeb.pdfIn PDF document text
    • http://fkhd.cz/data/img/bekisefijapomivulatifejed.pdfIn PDF document text
    • http://www.alexgis.com/siteuploads/editorimg/file/30363816926.pdfIn PDF document text
    • http://ngoinvest.com/uploads/ckfinder/files/wakoxunigabimemewesitir.pdfIn PDF document text
    • https://quanghuydulich.vn/img_duhoc/files/59887158251.pdfIn PDF document text
    • http://dzbnf.com/upload/file///menuxeweran.pdfIn PDF document text
    • http://fine-trading-knotwork.de/uploads/media/37049742313.pdfIn PDF document text
    • http://cpk.by/ckfinder/userfiles/files/90240127021.pdfIn PDF document text
    • http://jinruily.com/UploadFile/file/20210907155052145.pdfIn PDF document text
    • https://bluza-shop.ru/content/File/25028531814.pdfIn PDF document text
    • http://binhchuachay.info/Images_upload/files/16976176261.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_off0000f3af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AF 10300 bytes
SHA-256: 47ca6930a88348422675831f448bbe7e276b735f3183e12e4908defc4b0068fe
font_01_sfnt_off00010ab1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB1 18392 bytes
SHA-256: 35c91919815e7d44d1550497d5841ec3f1f84eb194ce35db3f49d2f2fbd39b15
font_02_sfnt_off000139a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1