Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6908736d3c6b582…

MALICIOUS

PDF

86.4 KB Created: 2021-09-19 08:38:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d6b080dd66eb6ba08a2c8b369bd52873 SHA-1: b84e04125417ff8c2f96ca52aeebc17603752daf SHA-256: b6908736d3c6b582741b25107681ba9b5b63bdbe9e1e4a3242d707de78731dae
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to potentially compromised or disposable domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a link farm structure, and 'ML_NYX_PDF_MALICIOUS' suggests a high probability of malicious intent. The document body is heavily obfuscated and unreadable, preventing a deeper analysis of its specific lure, but the overall structure points to a malicious distribution or SEO poisoning scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://ijacr.net/assets_admin/ckfinder/core/connector/php/uploads/files/20447716312.pdf In PDF document text
    • http://kovove-ploty-brany-zabradli.cz/UserFiles/File/23959420045.pdfIn PDF document text
    • http://verypool.cn/images/upload/File/lemoduzirutudaj.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/911269774.pdfIn PDF document text
    • http://phaptangpgvn.net/app/webroot/upload/files/41622433654.pdfIn PDF document text
    • http://xn--42-6kcdlkbomh7beggito5p.xn--p1ai/userfiles/file/mifamavigajaxazokerun.pdfIn PDF document text
    • https://ecosolar-energy.com/piceditor/file/sexidaroberizowonezud.pdfIn PDF document text
    • https://www.hkha.com.hk/ckfinder/userfiles/files/toduwixefazopubeluw.pdfIn PDF document text
    • https://rentcar888.com/uploads/files/202109100602574395.pdfIn PDF document text
    • http://gnatowski.pl/attachments/file/64772451067.pdfIn PDF document text
    • http://fsoa.cn/userfiles/file/69215056642.pdfIn PDF document text
    • https://incense888.com/uploads/files/202109101054162027.pdfIn PDF document text
    • http://www.dreamstoreonline.es/ckfinder/userfiles/files/67132444900.pdfIn PDF document text
    • http://mai-colle.jp/userfiles/file/rabenobeninatok.pdfIn PDF document text
    • https://marjoyunlar.com/calisma2/files/uploads/63363087491.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613675ff08bfd---24872112888.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/5686de8d5a2b4291018a2c6ff4011717/3439491652.pdfIn PDF document text
    • http://flathead.herosuite.com/userfiles/file/zatesozakopel.pdfIn PDF document text
    • http://www.logistiekverbeteren.nl/ckfinder/userfiles/files/98695246145.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/ee5fcb4e246e04023b756f4fd62940f0/zizekuvopipiv.pdfIn PDF document text
    • http://olddieselparts.com/ckfinder/userfiles/files/21446741683.pdfIn PDF document text
    • http://www.travelwithtaangoo.com/img/file/17667939081.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/49940565216.pdfIn PDF document text
    • http://bigdoughpizza.com/uploads/files/jononenewopogul.pdfIn PDF document text
    • http://cambridgekapurthala.com/damana/userfiles/file/99442633461.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=how+to+record+phone+call+androidPDF 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_off0000efab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAB 10520 bytes
SHA-256: 621adb703b6e6f0e18e577ee735be3ad56274bd3c4f48e084d22e3fa9103bf21
font_01_sfnt_off00010782.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10782 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F94 17220 bytes
SHA-256: 9118cace209f846d15f076db2cac100a7ab2cec06e7b1dc371da71a0f4645da2