Malicious PDF — malware analysis report

Static analysis result for SHA-256 25fc0ea75cf19763…

MALICIOUS

PDF

72.4 KB Created: 2021-09-18 23:52:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 90464c1306f239befed618dac521ec8d SHA-1: 6d296089c6b6c2a42c51b8ecf35c72a06afa5aca SHA-256: 25fc0ea75cf197636693c9bf2c8fc4ecda72230ae8940bcab87af77030797839
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of embedded URLs and the PDF structure suggest it's intended to trick users into visiting these sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://synerhu.ru/uplcv?utm_term=comic+text+maker
    • https://minhkygroup.com/luutru/files/witamofijutufukugesad.pdf
    • https://aneri12.cz/res/file/76392583064.pdf
    • http://metapolar.hu/tmp/53279402670.pdf
    • http://muacuoi.vn/Pictures/files/71687949456.pdf
    • http://ohsongpharm.com/ckfinder/userfiles/files/99499726883.pdf
    • http://chemsdano.com/upload/files/79314324032.pdf
    • http://www.bluewhaleline.com/image/upload/File/ragukufirilenapemevuvaji.pdf
    • http://www.dawnrotaryclub.tw/UserFiles/files/64223864042.pdf
    • https://tahuacoop.com/cms_gpadmin2015/sgi_userfiles/userfiles/files/61702565865.pdf
    • http://xn--80aaffebba2apgigwiiececnggk9e4k.xn--p1ai/pict/file/45555952745.pdf
    • http://memsports.com.br/admin/libs/ckeditor/ckfinder/files/99246400096.pdf
    • http://greenmodels.ru/uploads/files/gumakoguzajakarezu.pdf
    • http://www.psoealora.es/ckfinder/userfiles/files/81336742726.pdf
    • https://cottonweb.net/userfiles/file/vozubo.pdf
    • https://stockbauer.hu/uploads/file/7982124382.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/161385834603c7---pijujijegede.pdf
    • https://bankubezpieczen.pl/userfiles/file/dezozotulo.pdf
    • http://posicert.com/upload_fck/file/2021-9-5/20210905065919757664.pdf
    • https://asiarsolutions.com/userfiles/file/fonelenoxixiwowora.pdf
    • https://watfordfairtrade.org/app/webroot/img/files/bolibuxitibumum.pdf
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/73hd3od3vkqmmmtmg6hg6l124r/66894015673.pdf
    • http://alexdisinfestazioni.com/userfiles/files/18513704911.pdf
    • https://advantagelic.com/singhania/downloads/file/58477371060.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/161412c6eb8f16---zigebezatavafakudav.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bbb2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBBB2 16792 bytes
font_01_sfnt_off0000d3c9.bin
c55a8946bcd87e1136ba029543e49e6f310a9ca716da8712c2c492552daeb2f6
pdf-font-stream PDF embedded font (sfnt) at offset 0xD3C9 10296 bytes
font_02_sfnt_off0000eb0c.bin
19969d9bd0bcf08aaac1706248264b0bfc94e8e51f627d25c6ca167bc5f579ea
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB0C 16000 bytes