Malicious PDF — malware analysis report

Static analysis result for SHA-256 43626899f2e07216…

MALICIOUS

PDF

71.6 KB Created: 2021-09-25 04:57:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 50c86690673d433d515bb4bc41f15aa9 SHA-1: 0a6ad7bd69b013e836fc0d0354726c18830de91b SHA-256: 43626899f2e072162dc816a9e145e4c815057f86d67446be122cab08f6f89dee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs that form a link farm, with several pointing to compromised CMS upload directories or disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with common phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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=android+head+unit+xda PDF link annotation
    • http://erictex.com/ufiles/files/telemofesut.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/bdebd1d13c254736f4311fd3fe13222e/nonavutiganatubofaseraze.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142f8db2ab8a---95783353714.pdfIn PDF document text
    • http://studiotecnicodambra.eu/userfiles/files/pasitipitamov.pdfIn PDF document text
    • http://amicissiapiemonteisa.it/userfiles/files/wopoporevutagelo.pdfIn PDF document text
    • https://tiguan-wiki.ru/file/gisarufolapi.pdfIn PDF document text
    • http://kup-vino.cz/web/ckfinder/userfiles/files/bipejejiliwavad.pdfIn PDF document text
    • http://ntouioc.ntou.edu.tw/ckfinder/userfiles/files/58152066431.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/29973029151.pdfIn PDF document text
    • http://myphamhelios.vn/luutru/files/godoj.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/bc0cfb0eb77c9d78d23f40c115009832/fusepidu.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/lonigubonelikokelixawon.pdfIn PDF document text
    • http://challendor.com/fckeditor/upload/file/jexurigipometizosav.pdfIn PDF document text
    • http://gmei.lt/ckfinder/userfiles/files/96133453778.pdfIn PDF document text
    • http://saaretravel.ee/images/file/womerosis.pdfIn PDF document text
    • http://qazaqbanki.kz/data/content/files/xubejigekafezokibefifa.pdfIn PDF document text
    • http://p-jtech.com/userData/board/file/5799825447.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/2505437701.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/rawapumigoruk.pdfIn PDF document text
    • http://szentdorottyapatika.hu/files/fejoxupomewuxunuw.pdfIn PDF document text
    • http://kingkady.com/uploadfile/files/38945823114.pdfIn PDF document text
    • http://vhshf.de/File/janoviziko.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161350626cd3ea---wopan.pdfIn PDF document text
    • http://billsky.ee/files/file/bajabadat.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_off0000b4bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4BF 17408 bytes
SHA-256: 0fa7bdc397a2aeda44a4dd1aa49356441e16fcf3dd09d87660ba4d4a7112c768
font_01_sfnt_off0000e17b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE17B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f992.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF992 10316 bytes
SHA-256: 31868e7acddbf1c65a34a61060a57803cf0737b46c92958bd7b20fd552aaebd1