Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d8cb8981a4cac4a…

MALICIOUS

PDF

75.0 KB Created: 2021-09-06 11:33:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 15ba2f1d0787d869a590638b0c81bb3f SHA-1: 16a789c4b06581291701b575c840faa8953a0448 SHA-256: 4d8cb8981a4cac4a33658f9f19946fa905548de08221efc2349f34387fb22863
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which appear to be hosted on compromised WordPress sites or disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the PDF structure strongly suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://laborke.ru/uplcv?utm_term=important+english+words+used+in+daily+life+pdf PDF link annotation
    • https://m-astar.com/UserFiles/files/26726291254.pdfIn PDF document text
    • https://hoalavender.net/upload/files/80165422319.pdfIn PDF document text
    • https://www.akilciilacdernegi.com/ckfinder/userfiles/files/wedexoturedebi.pdfIn PDF document text
    • http://www.celso.org/download/37242374060.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/e22cde022d47d4425bceea8e4dfac0ca/lupokukigifuv.pdfIn PDF document text
    • http://ackerviewguesthouse.com/userfiles/file/bulubez.pdfIn PDF document text
    • https://magerp.org/upload/files/bejobinivokituvofusap.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/a3j63ggigfkpj28s9qu4vkqbhs/28810695879.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/43714825758.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/42046e4c0e9c49a0d015d1d2f2aa37ec/85525805623.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16099e9aa34d7c---mesanozupobebezunamit.pdfIn PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/80190321355.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/fuxebedu.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/0620a9cb5d36221c97362985604d9434/79880189659.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160da7ff62ea39---81979558810.pdfIn PDF document text
    • https://llsindia.in/FCKeditor/file/77415907212.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/903dd20e1c4d6209cdbcf2192b2c6e27/nipodejivewekepin.pdfIn PDF document text
    • https://bookatowncar.com/userfiles/file/19282825664.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/41702891599.pdfIn PDF document text
    • https://vaynhanh365.net/contents/files/77716174080.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/miradepazonituke.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/2c98bd9ca11a3a4c9844426ffc55636c/81119884789.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/9cf1ca9542f635baa38cc18fa172128a/lavesedotoweralubi.pdfIn PDF document text
    • http://vinhthuan.com/upload/files/58085952418.pdfIn PDF document text
    • https://tsydesign.com/userfiles/jws/files/zunojuw.pdfIn PDF document text
    • 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_off0000c0ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d911.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD911 16912 bytes
SHA-256: 349cb611c212b0b39318a9abc17e76a657887609bf8b1397032bbabfd3dff09d
font_02_sfnt_off00010454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10454 11196 bytes
SHA-256: f6fbf230a4826771c4c1e837f819b7467fc0ba8a325b98a5a0766dfd23f01d16