Malicious PDF — malware analysis report

Static analysis result for SHA-256 481918fe8d1e5c5c…

MALICIOUS

PDF

75.5 KB Created: 2021-08-08 11:46:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ea4b5060ce3dfdf3942bb5e9493640b5 SHA-1: f4ae78d571487e3a4969f5d0cd5f576b2d206e8a SHA-256: 481918fe8d1e5c5c7c410c2bc356108cbdab94211d6b7b3bd968d8f6ec2567af
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous URLs, many of which are hosted on compromised WordPress sites or disposable domains. The ML classifier strongly indicated maliciousness, and the presence of multiple external URIs suggests an attempt to redirect users to potentially harmful content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://chokysitohang.com/Uploads/userfiles/files/46421633108.pdf In PDF document text
    • http://absolutelyneon.com/userfiles/file/labij.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/7be3778751db093b74915f5d5f340bbf/sanaxukoziwejovemojo.pdfIn PDF document text
    • https://anna-bel.com/app/webroot/files/userfiles/files/23794858637.pdfIn PDF document text
    • https://combrooncom.com/contents//files/73370687454.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086e2b885b07---bifasefakuropilate.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16100b7436914b---92745714588.pdfIn PDF document text
    • http://kunmobile.vn/files/uploaded/20210709/file/28405893383.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160787240a0982---19339292893.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/e0d6d979c293211673495080ebb2ae3b/kokujipirawidewodetixe.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/2dbef034e187260eb86a0ddb2d4285eb/gikiwotu.pdfIn PDF document text
    • http://al-bandak.com/userfiles/file/7642699984.pdfIn PDF document text
    • https://ewt.cz/res/file/fepilo.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/movoniter.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608657c0ed791---guwodukoboro.pdfIn PDF document text
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210513031342.pdfIn PDF document text
    • http://matraholding.hu/images/userfiles/files/19405878820.pdfIn PDF document text
    • https://t2sc.me/userfiles/tepajusegatenakusijogow.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/13ae745c12ebe559ecc0373ad3633c42/xanufalonutabokojawije.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/ipbhckcig9d51pn0f16nhhkaoj/zowujumum.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160e536a80cc7e---timidaletukijuzi.pdfIn PDF document text
    • https://menu2uplus.com/images/file/87939213723.pdfIn PDF document text
    • https://senarathgroup.lk/assets/media/file/jipeworulogegefefori.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=barron%27s+sat+subject+test+physics+11th+edition+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_off0000be97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE97 11296 bytes
SHA-256: 930a5b062b95646e5bd349cdeceb8ee22dee0bada8c0c89f342b1c5aab56e0bf
font_01_sfnt_off0000d8fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8FC 18732 bytes
SHA-256: 8c9c31291b26c8b7a8951bdfb92ac6f88aefb32f08b85a80ff9d7468b7192923
font_02_sfnt_off000107d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1