Malicious PDF — malware analysis report

Static analysis result for SHA-256 b131e79c36a24cd6…

MALICIOUS

PDF

80.1 KB Created: 2021-09-11 01:29:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 35d3be9d9e8a4876bea208018fe11dc6 SHA-1: 2383be8267bf267727e8cdd8afaf42bbb3f70073 SHA-256: b131e79c36a24cd6de086eb61c82b9cfaf847ef9fedce36b08bbbc2ad81f86d6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, presenting numerous URLs that redirect to various domains, some of which are hosted on compromised CMS uploads. The primary purpose appears to be directing users to external sites, likely for phishing or malware distribution, under the guise of content marketing.

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 http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vemifukaba.pdf In PDF document text
    • https://atvatextile.com/upload/ckfinder/files/kajiruxoxenidilevig.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/0688e43f1f0fd86886d96fdff7282cf8/lefamomegawexosa.pdfIn PDF document text
    • http://clevio.biz/fckUpload/file/jolugul.pdfIn PDF document text
    • http://cyc.cz/pictures/clanky/files/zoxuxenekulofena.pdfIn PDF document text
    • https://zagi.hr/files/99475819162.pdfIn PDF document text
    • https://xn--80ag1a2a.xn--p1ai/files/file/rabavagelagojirud.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/161328e3898fef---xesejezakapen.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/ravugowejinovixewuwedoxeg.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/vn2i2pi51vnjh211ugca9lb7s5/87636462608.pdfIn PDF document text
    • https://sysyanginguvenlik.com/uploads/files/vojofurupisu.pdfIn PDF document text
    • http://xn--22cjbbm2eyae3ehabdb4kqdtae3dxnnc1fhf.com/user_img/files/42632278834.pdfIn PDF document text
    • http://escritacontabilidade.net/fotos/news/file/vesijom.pdfIn PDF document text
    • https://m-astar.com/UserFiles/files/53549595969.pdfIn PDF document text
    • http://ersenergy.com/UserFiles/file/41807754873.pdfIn PDF document text
    • https://profix.fr/ckfinder/userfiles/files/dirimeduvanoraxufiz.pdfIn PDF document text
    • http://serviphony.com/tinymce/jscripts/tiny_mce/plugins/phpimage/phpimage/upload/images/file/dusun.pdfIn PDF document text
    • http://zjbfjt.com/upload/files/tuvubabububimesawemagaw.pdfIn PDF document text
    • http://naturalmis.com/userfiles/file/datoxefupotixepe.pdfIn PDF document text
    • https://wfca-czech.cz/temp/userfiles/files/3533777415.pdfIn PDF document text
    • https://hijaulumut.com/contents/files/91892059145.pdfIn PDF document text
    • http://gruppocinofilomarsalese.com/userfiles/files/zezorolezukigikikubotow.pdfIn PDF document text
    • https://ihappywash.com/uploads/files/202109081500472348.pdfIn PDF document text
    • http://sladkiy-ostrov.ru/userfiles/files/60651606070.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=content+marketing+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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d5cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5CB 17104 bytes
SHA-256: 995bf647903dc338ac2421da79d75f7fd4437ea23746611927e85c9c0e47d507
font_01_sfnt_off0001026d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1026D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A84 10752 bytes
SHA-256: 295f614f5b997aa0893bce93066e9aab64b3f7e0caad10e71c87c69226746e1f