Malicious PDF — malware analysis report

Static analysis result for SHA-256 828bb433d129a5da…

MALICIOUS

PDF

76.0 KB Created: 2021-08-20 01:50:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c130fba1c4e35afb2c26b73c97bc714b SHA-1: 119ffa42806764a2588cd44536dc96dabca73e26 SHA-256: 828bb433d129a5da43db156e9cbfbede6836c90bc2d1c8915e7fe93447435147
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or are part of link farms hosted on disposable domains. The primary attack pattern involves luring users to click on these links, likely leading to further malicious content or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://crysiq.ru/uplcv?utm_term=how+to+replace+a+pull+cord+on+a+snapper+lawn+mower PDF link annotation
    • http://vattuxaydunghl.com/userfiles/file/11240059575.pdfIn PDF document text
    • http://czpohledavky.cz/userfiles/files/polid.pdfIn PDF document text
    • https://aquarell.ro/userfiles/file/xadigeboniworef.pdfIn PDF document text
    • http://spreewaldatelier.de/img/editor/file/59092343279.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b42e0f53119---19901405544.pdfIn PDF document text
    • http://headlinesdinerla.com/uploads/files/nexozolo.pdfIn PDF document text
    • http://wecans.net/_UploadFile/Images/file/89326366357.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a283172235c---fuxonuki.pdfIn PDF document text
    • https://llibreriaha.com/img/events/file/49103502415.pdfIn PDF document text
    • https://polandpools.com/contents//files/31793264355.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/qiv60otoitd1aecari1tunb0j6/xagovi.pdfIn PDF document text
    • http://orderkiwicafe.com/uploads/files/bufaxakafavokoridojanora.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/btgis60hbd4jfpc8b7uk5vvlf2/tebuxejatora.pdfIn PDF document text
    • http://krzysztofmalec.pl/gfx/fck/file/83328622178.pdfIn PDF document text
    • https://bomberosdenavarra.com/userfiles_nexo/files/lopudutazavixa.pdfIn PDF document text
    • https://stallion-international.com/userfiles/file/77610212524.pdfIn PDF document text
    • https://freebcard.com/ckfinder/userfiles/files/45176818043.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/68382760520.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-8-11/20210811234440606442.pdfIn PDF document text
    • https://hrmconsulting.biz/upload/files/89150305395.pdfIn PDF document text
    • https://gencerenerji.com/resimler/files/72820874256.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/61c733d00af4b0f0fea42115959505a6/jepos.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160aa3a6ec1a7f---luximakixoparofojafofi.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_off0000c720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC720 10760 bytes
SHA-256: 1da7ffe9876e4b6a644db0a28c9c78dc3bc4ea9a2a4923f5c9145d7cb3be0a5a
font_01_sfnt_off0000dfe3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f7f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F5 15808 bytes
SHA-256: 3d98fc299e16e3203269ddd9fe50b2f0e87219ff17da56f3d28118fc86790dfd