Malicious PDF — malware analysis report

Static analysis result for SHA-256 935982d848b2642d…

MALICIOUS

PDF

95.0 KB Created: 2021-09-21 07:10:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ec3547cb19bb31897f95ba45c0b2a942 SHA-1: 3eab7c6af7db68677c091a3a3582c9f14977684d SHA-256: 935982d848b2642d26b0c1a74267fd6c2bce27aef1475072e9ea276ccf9cc92a
96 Risk Score

Malware Insights

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

The PDF contains numerous links, with several pointing to compromised CMS upload directories and disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, limiting the analysis of specific execution techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9889

Heuristics 5

  • 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://lindendirect.com/tempimg/file/xuvemofowuberuwemegid.pdf In PDF document text
    • http://yotlist.com/uniformkontakt/userfiles/image/files/99902209802.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/kedusenurulirodabapubufa.pdfIn PDF document text
    • https://dichvuketoansg.com/luutru/files/9172502107.pdfIn PDF document text
    • https://namratalakhotia.com/userfiles/files/wogometinojevuvofup.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614451dc83e88---71079378790.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/d5k6sjfgn4mt002701vvukhtph/zakenirif.pdfIn PDF document text
    • http://www.ciesol.es/ckfinder/userfiles/files/tuseravuxigapojuxer.pdfIn PDF document text
    • http://markasib.ru/ckfinder/userfiles/files/pisukisurizudugefije.pdfIn PDF document text
    • http://circolonauticofavignana.it/userfiles/files/65336998211.pdfIn PDF document text
    • https://vidaleve.ind.br/ckfinder/userfiles/files/vegak.pdfIn PDF document text
    • http://www.s4b.nl/upload/files/xuxurubewujitavowe.pdfIn PDF document text
    • https://signika.pl/Upload/file/fivevaxala.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/lm58an6g7l7aipdpo6fmfl7dnq/62360114430.pdfIn PDF document text
    • http://gruppocaminiti.it/userfiles/files/bunozimagiwota.pdfIn PDF document text
    • http://erpos.sk/data/files/dumemu.pdfIn PDF document text
    • http://marathon-gexin.com/Uploadfiles/files/tokafutasetexe.pdfIn PDF document text
    • http://fuhua.tumujike.com/assets/upload/files/202109060054111774.pdfIn PDF document text
    • https://dolphinsolutions.net/ckfinder/userfiles/files/mobaremopoxorukika.pdfIn PDF document text
    • https://granitnet.hu/editor_up/dumaditej.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/uvr2o08js44duir0ckhupp0a4n/litowomajaz.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/34349169947.pdfIn PDF document text
    • http://wajl.net/img/file/2021914175927.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/bfb9e7dda02596decb9f28eed0ae8459/75216939549.pdfIn PDF document text
    • https://korvioinfotech.com/ckfinder/userfiles/files/bexotatusewiw.pdfIn PDF document text
    • http://cosmeticdermatologymiamibeach.com/uploads/data/files/43055367696.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/80742667246.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=free+locker+codes+for+vcPDF 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_off00011315.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11315 10148 bytes
SHA-256: a67238928301da1ea7d5cf959e086f8a04cc6be33c9d2241fff20cbbfd264505
font_01_sfnt_off000129e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129E0 17632 bytes
SHA-256: 1fd9abf38d2ead814c5a6b7d95e41275c75f598752152b52d03c6e2cddae6a83
font_02_sfnt_off00015616.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15616 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1