Malicious PDF — malware analysis report

Static analysis result for SHA-256 e21733b87baccae1…

MALICIOUS

PDF

69.8 KB Created: 2021-10-01 11:34:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 8c1c200ac8896da7241fb7f8790c6b9a SHA-1: 165dc48f06197582c52c66efdad325c864a4a5ce SHA-256: e21733b87baccae169da92e0577a5b82ed9ff273c831ec0d732b04b55c3f99c4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to host numerous links on disposable domains, a common tactic for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure itself likely contains embedded links or JavaScript to redirect users to the identified unknown URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://strahovka66.ru/userfiles/file/98547800789.pdf In PDF document text
    • http://jungam21.com/upfiles/file/1632902386.pdfIn PDF document text
    • http://suachuamaydemtien.biz/userfiles/file/87952377597.pdfIn PDF document text
    • http://edilgroupdigiovanni.it/userfiles/files/32446453964.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/zikumome.pdfIn PDF document text
    • https://gtnet-engine.com/ckfinder/userfiles/files/devumiga.pdfIn PDF document text
    • http://helenhotel.vn/upload/files/lixine.pdfIn PDF document text
    • http://architettoangeli.it/userfiles/files/fuwadupurufegof.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210909051840.pdfIn PDF document text
    • http://mexxeopaint.com/upload/files/54647789888.pdfIn PDF document text
    • https://namkhoasaigon.vn/web/images/files/62609553962.pdfIn PDF document text
    • https://gastriklandsbf.se/UserFiles/files/74690942769.pdfIn PDF document text
    • http://netcentricnj.com/ckfinder/userfiles/files/gidorisamexukigexa.pdfIn PDF document text
    • https://shaksheer.com/app/webroot/upload/files/gufiweredelozalakazuv.pdfIn PDF document text
    • http://fk-fudosan.1nino3.com/app/webroot/img/userfiles/files/7833753881.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/55242868834.pdfIn PDF document text
    • http://giprozdraw.ru/ckfinder/userfiles/files/4757317037.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/radatuxeniza.pdfIn PDF document text
    • http://retailcop.ca/files/momumibedeb.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d4d6f83377---kimotuwadosuturaxigitaveb.pdfIn PDF document text
    • http://tidomusica.com/uploads/files/202109090727507777.pdfIn PDF document text
    • http://www.fdconsult.qa/public/uploads/cms_files/14044509066.pdfIn PDF document text
    • http://gainliving.com/upload/editor/file/rasavodagijajosixaruzozad.pdfIn PDF document text
    • http://dlzj.net/upload/files/20210905175913991699.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=very+high+graphics+games+for+androidPDF 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_off0000af2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF2C 11008 bytes
SHA-256: 67d7cc4b1e1226b68b9b7b6ab01f62f588ea3e43dce4f6ee683ab76f8bf71f09
font_01_sfnt_off0000c865.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC865 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e077.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE077 15600 bytes
SHA-256: 5ae76cbd5fa6c87beebd052610a932e5bc8917c88de9da065b86fd375a6393b9