Malicious PDF — malware analysis report

Static analysis result for SHA-256 b91fe3a2f8a257b6…

MALICIOUS

PDF

91.2 KB Created: 2021-09-04 10:50:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: f1f45370dd7f401aa90b7b082afec3cd SHA-1: 29f6d630e89e8b09eda640f4938c5dafc18f0eed SHA-256: b91fe3a2f8a257b6d08e3ab200bc976d3762ea12b5939739781f7c2f3e4daeb1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9726

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://newat.ru/wp-content/plugins/super-forms/uploads/php/files/58384aa76280eb4998143a0223aa901f/devitivojoti.pdf In PDF document text
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/nas1b6kmqjipfmh9ke8pn3tpoi/5545786803.pdfIn PDF document text
    • https://soechi.com/userfiles/file/xegetepam.pdfIn PDF document text
    • http://nguyenquangcomputer.com/upload/ck/files/86183903143.pdfIn PDF document text
    • http://unicorn-furnitures.com/d/files/42291532379.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/tozenexuzidifexebimir.pdfIn PDF document text
    • http://allycatering.com/userfiles/88027213523.pdfIn PDF document text
    • https://vegastel.eu/components/com_mijoshop/opencart/image/data/files/37901496680.pdfIn PDF document text
    • http://dolinakrzeptowa.pl/public/upload/ckfinder//userfiles/files/49198666593.pdfIn PDF document text
    • https://quaint-house.com/images/blog//file/44718800988.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf47d117a69---64022635810.pdfIn PDF document text
    • http://lakesideterracecondo.com/clients/41361/File/1226445134.pdfIn PDF document text
    • https://evergreencans.com/userfiles/file/69720865204.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/ftah4ad5i846qt6pcd2ftkk1fb/61186617874.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/df2a824cd341bb350dda3e5f5af05db2/59221114445.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/seet8c2mrubgl7cgvcr5i3pfqf/9247933621.pdfIn PDF document text
    • https://erdenetpost.mn/userfiles/files/98888230879.pdfIn PDF document text
    • https://www.stock2morrow.com/ckfinder/userfiles/files/72601326821.pdfIn PDF document text
    • http://tourister.kr/userfiles/file/29713415327.pdfIn PDF document text
    • http://stavo-bazar.cz/userfiles/file/vidusajexabeko.pdfIn PDF document text
    • http://asckhn.com/acskhn/userfiles/file/13167941128.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607859bc4ffe1---46593798716.pdfIn PDF document text
    • http://talcmanagement.com/uploaded_files/userfiles/files/17992783716.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160f71a373273d---lamulew.pdfIn PDF document text
    • http://ural-resyrs.ru/data/file/resiv.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16072241485404---kafaxabemegilo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=%D8%AA%D8%AD%D9%85%D9%8A%D9%84+%D9%83%D8%AA%D8%A8+%D8%B9%D9%84%D9%85+%D8%A7%D9%84%D9%86%D9%81%D8%B3+%D8%A7%D9%84%D8%AA%D8%B1%D8%A8%D9%88%D9%8A+%D9%85%D8%AC%D8%A7%D9%86%D8%A7+pdfPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_006_off000110b6.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x110B6 23788 bytes
SHA-256: 31b476fc042a73a815a020743faa28cc474f3175f80f830f116f1225678b70bf
font_00_sfnt_off0000cce0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCE0 9372 bytes
SHA-256: ab692011bb810b4091e5b6863c1468cc19624005727076e0e42723678ec61724
font_01_sfnt_off0000e0bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BF 18876 bytes
SHA-256: 26d1bdcd4bab9c461b40c885197feb0bc8f18f1e1cd97da45dc3b5128d8e4d51
font_03_sfnt_off00013a5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A5B 19648 bytes
SHA-256: 150dd7aaadf5a6cef5c208dd14c545bb027e012201c1afbab7cc7a4d07524f26