Malicious PDF — malware analysis report

Static analysis result for SHA-256 b134bd0cfca8a36a…

MALICIOUS

PDF

85.2 KB Created: 2021-09-09 13:07:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d5248721b79e12ce9d570859ca1b0605 SHA-1: 6c280e3ce78502c9fcf6ba949876346f1dd60d48 SHA-256: b134bd0cfca8a36adbbf3615db805005ba92bac1cf68945fb856322fc43ebe0d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document is a link farm designed to redirect users to numerous external sites. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm heuristic point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://proleague.dk/userfiles/file/67559417379.pdf In PDF document text
    • http://bookblog.kr/data/file/files/gedigoja.pdfIn PDF document text
    • http://kemxoi.vn/app/webroot/files/images/pages/files/9738797472.pdfIn PDF document text
    • https://ms02bet.com/contents/files/gakitatavipuwa.pdfIn PDF document text
    • https://supermagnum-bg.com/ckfinder/userfiles/files/6948147734.pdfIn PDF document text
    • http://xn--80aiddhbkcq5bcaz.xn--p1ai/upload/files/78151417394.pdfIn PDF document text
    • http://kdwatch.net/upload/files/2021090404292386.pdfIn PDF document text
    • http://acelybio.com/upload/files/zesalejuxariz.pdfIn PDF document text
    • https://vargyasnekonyveles.hu/kepek/other/file/xijina.pdfIn PDF document text
    • http://sostrevalli.it/userfiles/files/35574778264.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136cda030fee---68284900135.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/32357997578.pdfIn PDF document text
    • https://paradigma.bg/uf/file/38358575976.pdfIn PDF document text
    • https://nieruchomosciprzetargi.pl/files/file/gurezaxifiwapedikifisunak.pdfIn PDF document text
    • http://maihome.hu/admin1/file/taxibuvunelosenevazirad.pdfIn PDF document text
    • http://krevue.cz/UserFiles/File/39971790641.pdfIn PDF document text
    • https://unitedfightalliance.com/ckfinder/userfiles/files/48407596178.pdfIn PDF document text
    • https://mobisteelegypt.net/userfiles/file/10275923443.pdfIn PDF document text
    • http://nmways.com/uploads/fckupload/file/woliwuzupuvokavizajokixem.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/84563370176.pdfIn PDF document text
    • https://neksav.com/upload/ckfinder/files/refeniwumisejatol.pdfIn PDF document text
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/85307192154.pdfIn PDF document text
    • http://shacklefordlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/loset.pdfIn PDF document text
    • https://baongochoa.com/upload/file/53767699581.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=http+injector+telegram+2021PDF 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_off0000dcdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCDF 10964 bytes
SHA-256: aa6c8b4821bbfa1c4c30c501542d8ee489f91ad0a0d918cfdbba65d3987c1676
font_01_sfnt_off0000f648.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF648 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E5A 21900 bytes
SHA-256: ef7b76bfee8ac0199b1b296c91d59fd7f44f92ff5c5ca55830d5e42548ff7e5e