Malicious PDF — malware analysis report

Static analysis result for SHA-256 86ba5c8728991d70…

MALICIOUS

PDF

81.8 KB Created: 2021-09-18 19:30:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5a1dd35ec313901a6af94b6ec95517fe SHA-1: be691f6b6c4b7804980f7ebdd7731b11a8fa840e SHA-256: 86ba5c8728991d70b2b8fa86d5d823a0795d0885d3a6cdcba35f201fd111559a
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many embedded URLs pointing to potentially compromised websites or disposable hosting. These links are likely used to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://irlanc.ru/uplcv?utm_term=redmi+note+9+fix PDF link annotation
    • http://doggystylzgrooming.com/admin/photos/file/kexup.pdfIn PDF document text
    • http://aqcorth.specialty-match.com/upload/files/50709424598.pdfIn PDF document text
    • http://mariancozma.com/_user/file/95482043604.pdfIn PDF document text
    • http://picart-personal.pl/fckupload/upload/file/3784825218.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bcead0ef01---sosupejat.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/d43cfc5495c65f556bd0b46edc1e30d5/tonokexeguj.pdfIn PDF document text
    • https://www.nickelmarket.co.za/includes/ckfinder/userfiles/files/23522270045.pdfIn PDF document text
    • https://el-tall.pl/pics/file/63188496375.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/suxifubifetoxewezuwidome.pdfIn PDF document text
    • http://umrllc.com/userfiles/files/ruforafozawawadi.pdfIn PDF document text
    • http://pincesorvarshop.hu/editor_up/zulofomokojimidox.pdfIn PDF document text
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/walasagamujiv.pdfIn PDF document text
    • https://nepalonlineexam.tisaracademy.com/userfiles/files/12002061605.pdfIn PDF document text
    • http://tianlanip.com/filespath/files/20210903210325.pdfIn PDF document text
    • http://tabouligrill.com/ckfinder/userfiles/files/53558541672.pdfIn PDF document text
    • https://corpus.bg/files/fck/file/wefebumivikimozuxagagosi.pdfIn PDF document text
    • http://vina2002.com/uploads/files/fogododis.pdfIn PDF document text
    • http://szentistvanpatika.hu/upload/file/80017559351.pdfIn PDF document text
    • https://transmar.biz/ckfinder/userfiles/files/72623046255.pdfIn PDF document text
    • https://shaplaconsulting.com/app/webroot/ckfinder/userfiles/files/zuwilatumefukifafixekajig.pdfIn PDF document text
    • https://cfaegaianascente.pt/portal/userfiles/files/xisibosijebokeko.pdfIn PDF document text
    • http://nbnjl.com/userfiles/files/fikozujib.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16130c425ac2cf---rawuzi.pdfIn PDF document text
    • https://olterus.org/contents/files/87285180723.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_off0000dbc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC5 17824 bytes
SHA-256: 4fe57404f1136a6a0b4a08f77e6c3e7081c02f81ce6e46d050a59271589f7297
font_01_sfnt_off00010a72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A72 10352 bytes
SHA-256: d821d7556fa2ed0f4ce369bed1d9b0352fd1621aa728523c5234c8ca23e83a0d
font_02_sfnt_off000121dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1