Malicious PDF — malware analysis report

Static analysis result for SHA-256 ddffac081f1c34df…

MALICIOUS

PDF

68.1 KB Created: 2021-09-24 11:29:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c44526a7b68a253e1628837779642ff7 SHA-1: e83ae058a06347be216db3d6f5b99c22804334a7 SHA-256: ddffac081f1c34df74106bcc8011e4ce02259b2d032e40a83d09877aa1bf3812
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm. It contains numerous embedded URLs pointing to other PDF files hosted on various domains, suggesting a distribution or SEO manipulation scheme. While no scripts were explicitly extracted, the nature of the embedded links and the detection as a phishing trojan implies an intent to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://xn--2e0b30g3uq7pay7m.com/upload/fckeditor/file/52321239049.pdf In PDF document text
    • https://anctools.com/ckfinder/userfiles/files/79275653607.pdfIn PDF document text
    • http://coeb.eu/userfiles/files/91876659829.pdfIn PDF document text
    • http://slenderclub.cz/ckfinder/userfiles/files/buvobedivasizoroweleveve.pdfIn PDF document text
    • https://aep-tc.com/cache/fck_files/file/58899372252.pdfIn PDF document text
    • http://hylimusic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/lusidus.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/161423b61a5c8a---larapopan.pdfIn PDF document text
    • http://we-women.de/default/files/uploads/file/mulileguxato.pdfIn PDF document text
    • http://himalayakebab.irafbrothers.com/shipinc/userfiles/files/44435725654.pdfIn PDF document text
    • http://medicaldistri.com/ckfinder_files/files/vogisin.pdfIn PDF document text
    • https://tiemhoahaibara.com/data/dulieu/files/77222602981.pdfIn PDF document text
    • https://tekstilkentrehber.com/upload/ckfinder/files/57097988129.pdfIn PDF document text
    • https://ptogel2.com/contents/files/mawozimoluxegakanoduda.pdfIn PDF document text
    • https://dpengineerindia.com/admin/userfiles/file/bifodamanajotu.pdfIn PDF document text
    • http://pokorny-podlahy.cz/UserFiles/File/radusi.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/5668aa711425fb3fc14d7582c01c7a07/5930536416.pdfIn PDF document text
    • https://elegune.net/files/galeria/files/85991624297.pdfIn PDF document text
    • http://kvbm.org/pds/userfiles/files/68059141312.pdfIn PDF document text
    • https://barrier.exma.cl/ckfinder/userfiles/files/78147702824.pdfIn PDF document text
    • https://satbietthu.com/luutru/files/mozudibaz.pdfIn PDF document text
    • http://gnatowski.pl/attachments/file/fozunafotenabuxufan.pdfIn PDF document text
    • http://dgjinhak.kr/DATA/upload/files/202109070627185180.pdfIn PDF document text
    • https://lmbri.com/WYSIWYGImage/file/todolufibapejovumiwepogo.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/31552719947.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=pop+g+apkPDF 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_off0000b05d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB05D 14760 bytes
SHA-256: 84ba7639e10f69d427836205a07ac3f7c5da4f185b50921699c0cdccc012767d
font_01_sfnt_off0000d5c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5C6 9780 bytes
SHA-256: f0150f084b65f8e75e2cce2a053b7c654adcd8e543e3a6cb6ab86c466568d023
font_02_sfnt_off0000eb52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB52 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1