Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab328eeb86e87dc4…

MALICIOUS

PDF

75.1 KB Created: 2021-09-03 04:44:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 0a01568aa3c575c685594db423e5a3e4 SHA-1: c5cf7fa79330bbb8151d08a8106f7459b7640373 SHA-256: ab328eeb86e87dc42ac03bf690015beeed50d39978422bc13c41c8bee04df166
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, embedding numerous URLs that point to other PDF files hosted on compromised websites. This technique is often used for SEO manipulation or to distribute further malicious content, making the primary attack pattern the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://tcihk.com/userfiles/20404811376.pdf In PDF document text
    • http://barudan.hk/UploadFile/file/20210626092256687.pdfIn PDF document text
    • http://drxzhang.com/userfiles/file/14198479799.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/4bd62c14dcc3751900c7234cb7d1fa64/66174655692.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/qsgrb500790rt9lkhb7vt4eggv/29818779474.pdfIn PDF document text
    • http://cerrutistudio.eu/userfiles/files/libexepegitote.pdfIn PDF document text
    • http://belgium-ex.com/images/blog//file/logamamoxegobezedusisak.pdfIn PDF document text
    • http://beloit1962.com/clients/8/83/8368a4f838dea3176655029ae9e337da/File/lisamusemezukedog.pdfIn PDF document text
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/b3j26lcs8bttn7ujatb7a8d3d2/82648186696.pdfIn PDF document text
    • http://royalwedding.jp/images/blog//file/21566211901.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/wufijojinujowunija.pdfIn PDF document text
    • https://mimpiindah2.com/contents//files/97084034975.pdfIn PDF document text
    • http://deurenhanger.nl/userfiles/file/xirironoxotozed.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/9ue9hcbi72tqi1eel9of0bkrl2/tadoduvolodovavixorefikez.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608f1db226474---riwilibajevituxonen.pdfIn PDF document text
    • http://cesnek-vysocina.cz/UserFiles/File/vorolikajikurulonikub.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/14842281084.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/14983644254.pdfIn PDF document text
    • http://dlevitin.ru/fck_editor_files/files/99082641987.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16113e6c51e065---40109735961.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/2df7cf36a15f861e260ec9a56960194e/rokakefimelemevupipamefaj.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/vetazebuvawagonuvegejaluv.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16080ca7c6e2d3---34065776714.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=modern+steel+making+process+pdfPDF 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_off0000c275.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC275 11048 bytes
SHA-256: b8eeb3ea55bfba73a4cb66146954625fca33f2681e6b09771d5e42f2c5a8a8ad
font_01_sfnt_off0000dbf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF5 16852 bytes
SHA-256: 3b6605ed2d53b6412fd1484f4632769cbe43a46c4d2166d564c5d5ec1ed63f77
font_02_sfnt_off000106e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1