Malicious PDF — malware analysis report

Static analysis result for SHA-256 874bf36a87b2615c…

MALICIOUS

PDF

73.0 KB Created: 2021-09-12 13:17:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e7c91f3956c1172fd1d40ca322a20a59 SHA-1: bfba4ae75ae1dd64a10fe4339c578ee17c353dc3 SHA-256: 874bf36a87b2615c98d64f735c788b302cc60fa9c69e0e886800f2a7801d8a1b
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware download sites. The presence of embedded JavaScript (T1059.007) suggests an attempt to exploit vulnerabilities or perform malicious actions within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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.
  • 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 http://terlickodds.cz/www/www/fckphotos/file/72829976350.pdf In PDF document text
    • http://kaies.cn/upfiles/210901144158472279f49vuz.pdfIn PDF document text
    • http://szkolaprzybranowo.pl/ckfinder/userfiles/files/92896719781.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/dhq7u71uvuhlgcro97hbfe46q7/36171051981.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/40a932f80b5104a52bed505abdea5953/30519363112.pdfIn PDF document text
    • https://oceanflowerhotel.com/uploads/image/files/86264593813.pdfIn PDF document text
    • https://dehayemek.net/upload/ckfinder/files/77055751394.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/zizipefax.pdfIn PDF document text
    • http://hakanhurdacilik.com/userfiles/file/putagiluvepuxamigo.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/15356714921.pdfIn PDF document text
    • https://orrizon.ru/images/file/25485061592.pdfIn PDF document text
    • http://vaithun.net/upload/files/fawoxivilukopoxuzitured.pdfIn PDF document text
    • https://www.theoakshealthcare.com/my_content/js/ckfinder/userfiles/files/dirarovugijuzejurur.pdfIn PDF document text
    • https://www.ftha.org/admin/ckfinder/userfiles/files/funoverob.pdfIn PDF document text
    • https://sangolongphuong.vn/longphuong/news/files/bisumi.pdfIn PDF document text
    • http://llux.vn/uploads/files/zebanagi.pdfIn PDF document text
    • http://ginzaoakland.com/uploads/files/16654318801.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613d385c2d2de---69879228550.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/ckfinder/userfiles/files/pimageb.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/tejegepuzikafidenopipeko.pdfIn PDF document text
    • https://penmypoem.com/new/admin/uploadfiles/file/99172615142.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/20254432376.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/23242835967.pdfIn PDF document text
    • https://alpinashop.rudy-ra.com/files/11217773853.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=live+chat+app+download+for+androidPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bb45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB45 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d35c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD35C 10660 bytes
SHA-256: a3072c4bfb5f531f73672840f06e4330e31cb5a681646435e45c5b4f005e60fa
font_02_sfnt_off0000ebc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBC2 16612 bytes
SHA-256: d38d7ae4249bbeaddad7f4eb65a4524868adcf63ceb8c767d1c3d2b0be51e928