Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ca4598a378ab470…

MALICIOUS

PDF

79.8 KB Created: 2021-09-04 16:06:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 6fc7e7129f5f496cda4e001f94a1bb1a SHA-1: 4d0142aef5dadebec4c15df22f5be0e405f550ae SHA-256: 6ca4598a378ab470e826887d2d12788ba10279839975cf00755e8cf3636e8985
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, presenting numerous URLs that point to compromised WordPress sites and other domains, likely serving as a distribution point for phishing or malware. The PDF structure itself is exploited to host these links, suggesting an attempt to bypass security measures through a seemingly innocuous document format.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://medvor.ru/uplcv?utm_term=rachel+carson+silent+spring+worksheet+answers PDF link annotation
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/itehjsifp1cdpbh747us7gi1cd/58485933774.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099f72e7446b---ziretinaxu.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072060a07c00---94450280291.pdfIn PDF document text
    • http://zzweien.com/d/files/25302245749.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1609b2f8d494aa---19194955397.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077e3901ac1a---mobekugage.pdfIn PDF document text
    • https://heritran.vn/uploads/news_file/52115724095.pdfIn PDF document text
    • http://ural-resyrs.ru/data/file/lifaginu.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/c70b292c1e0a19b998addc575ed7b8ba/1879627636.pdfIn PDF document text
    • https://musikkursus.dk/userfiles/file/texigupu.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb29b5a0a4---83635915812.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210604045103657515550.pdfIn PDF document text
    • http://panziofabian.hu/fck_kepek/49244278984.pdfIn PDF document text
    • http://studioarclab.eu/userfiles/files/duloxojuri.pdfIn PDF document text
    • https://vhssirimpanam.org/ckfinder/userfiles/files/86852971152.pdfIn PDF document text
    • https://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/29207807385.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/gaviludivewagibetadisag.pdfIn PDF document text
    • http://sam-global.info/files/file/68588140659.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/94184550566.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/160761109ac706---rirevifi.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_off0000d694.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD694 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eea6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEA6 16284 bytes
SHA-256: 086c781aa70e1f448e3ab8d80aa73eb0e05c5231c8a50fb3ba1603864a61ee64
font_02_sfnt_off000118a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118A7 10876 bytes
SHA-256: 4826c4ec27d94a3a864eafa2a3fb648e8dc34926c963ebd8fdccbeb381b84582