Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8916a30bd9e38ec…

MALICIOUS

PDF

75.4 KB Created: 2021-09-02 16:16:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3a31a3d9e88f5f909d1b91dbee02b114 SHA-1: 807ff706c4c3337b383bcacf3e136fe39848dfcb SHA-256: b8916a30bd9e38ec8b3e0158c6d95d3251772ec258d668b5c847e7b276da7915
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file flagged by ClamAV as a phishing trojan. It contains numerous external URIs, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness. No scripts were extracted, but the PDF structure and URL patterns are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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=gandhian+ideology+and+sarvodaya+movement+pdf PDF link annotation
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/16090a4106feb9---35300135059.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/xodakujosaxikitazezagi.pdfIn PDF document text
    • http://moje-stranky.eu/userfiles/file/fuwabupej.pdfIn PDF document text
    • https://fminterativa.net/cms/plugins/ckfinder/userfiles/files/11853286926.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/705a647cbc7086289fa0515d99bec13f/favimowirazulibed.pdfIn PDF document text
    • http://showplus.ae/userfiles/files/xewita.pdfIn PDF document text
    • https://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/qgkaffih1ka28h29ia5u1drtp5/13582758738.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/ba919035fd45a8db2da589f414f53abb/sisetovokafijebo.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/dh2sn8sq3d1c0vngr65s790f85/rutuxudokepubavewigirabe.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/160acbcf56e887---kopegefasuzixuvatobesav.pdfIn PDF document text
    • https://zenit-npk.ru/files/file/vejuxagenafatozonejiseje.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/160e8addf083cf---litujemiw.pdfIn PDF document text
    • http://ambulatorioveterinariocamali.com/userfiles/files/fupurimoxatixopivu.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/98589082528.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608f7a0980520---82775990345.pdfIn PDF document text
    • https://africanresearchcenter.com/userfiles/file/33308871867.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/2ll2sue8amirr88bj17i2rvo4k/fobobomubiribuxof.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160be14c09890d---33787034476.pdfIn PDF document text
    • http://mlead.net/images/e/file/25868780422.pdfIn PDF document text
    • http://healthywithhart.com/res/file/73758601511.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/9fd7285861dbff183e54755a73044f32/57587648295.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b305daa6af4---boferobozol.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210810141628.pdfIn PDF document text
    • http://www.deep2001.com/images/library/File/kunatibijasituj.pdfIn PDF document text
    • https://senfina.top/uploads/files/fibigaloz.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_off0000c2da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000daf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAF1 11164 bytes
SHA-256: 8eb2a91d85f4c015c786f7e01274a5fdf20c2dab93bdc98c651e962550b1dcbb
font_02_sfnt_off0000f4ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4AB 16956 bytes
SHA-256: ff244d07383199f96091ef4b0d2e9d9d44300384622513839b5f17a3a89a7639