Malicious PDF — malware analysis report

Static analysis result for SHA-256 a457a4891058f3d3…

MALICIOUS

PDF

82.9 KB Created: 2021-09-19 05:47:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 3145bfe327143cfb6f0bbcc53d27afdd SHA-1: 6aa6cbce9e18a34f5dfdbfdf733cbfdff577c6fa SHA-256: a457a4891058f3d33a1e39c470aca8831689c1fd8b8ace3703f1e0062af1f4d4
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier with high confidence. It contains numerous embedded URLs pointing to external PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a non-clustered link farm on disposable hosting, further supporting a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://garglob.ru/uplcv?utm_term=how+to+print+pdf+file+from+phone+to+computer PDF link annotation
    • http://www.salpasafarit.fi/tiedostot/files/wivufovufijan.pdfIn PDF document text
    • https://cr2tek.com/userfiles/Proj_Name/files/jozefef.pdfIn PDF document text
    • http://stavclearing.ru/upload/files/15561248288.pdfIn PDF document text
    • http://montpellier-business-plan.fr/mbp/upload/images/images/upload/ckfinder/62233429162.pdfIn PDF document text
    • https://terminarz.online/kosmetyczka/krakow/files/xaregul.pdfIn PDF document text
    • http://qbcar.ru/ckfinder/userfiles/files/88147018830.pdfIn PDF document text
    • http://thienminhgroup.com/uploads/userfiles/file/vanases.pdfIn PDF document text
    • http://odumakus.com/uploads/files/zusiwovebumof.pdfIn PDF document text
    • https://cli-kh.com/uploads/files/202109011549095903.pdfIn PDF document text
    • https://superpackeg.com/userfiles/file/3696869502.pdfIn PDF document text
    • http://tumakuruvoice.com/tumkurvoice/ckeditor/ckfinder/userfiles/files/98264790144.pdfIn PDF document text
    • http://boletos.luzservicos.com/ckfinder/userfiles/files/45409651629.pdfIn PDF document text
    • http://e2ingenieros.com/ckfinder/userfiles/files/38538198312.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140ca56962b4---64830238520.pdfIn PDF document text
    • http://tythb.com/uploadfile/files/12105467994.pdfIn PDF document text
    • http://nikolalepojevic5.com/multimedia/file/tenixem.pdfIn PDF document text
    • https://xcheck.vn/uploads/userfiles/file/zefovalowipivekuzufip.pdfIn PDF document text
    • http://alpes-de-haute-provence.proximeo.com/ckfinder/userfiles/files/besatotewaxipevokave.pdfIn PDF document text
    • https://traffictkt.com/viking1/uploads/files/11398210377.pdfIn PDF document text
    • http://holland-ex.com/images/blog/file/92145956880.pdfIn PDF document text
    • http://vet-spb.com/userfiles/file/fudemuwonogokozodasojal.pdfIn PDF document text
    • https://factorysales.com/userfiles/files/19771724772.pdfIn PDF document text
    • https://ibliberia.com/ckfinder/userfiles/files/ponugegivobimitazobipiso.pdfIn PDF document text
    • http://tindangnhadat.vn/upload/files/gexutemuk.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_off0000ddb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB7 18216 bytes
SHA-256: b56f5ec54d7ce4c18135426e184aba3fa78e6c9f7d0e2b33f4e152f59119af43
font_01_sfnt_off00010cf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001250d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1250D 10732 bytes
SHA-256: 6c0fdd7558a7f24fac0940f54f5cd53cad9196bc1e446a7e398f16e509eea2ae