Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf9befa1336c85fd…

MALICIOUS

PDF

68.7 KB Created: 2021-09-28 20:32:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 640196fd591cafcb29d0434b41828a04 SHA-1: 73bb393f7532d43c4b781204229ec41930cbb395 SHA-256: bf9befa1336c85fdd5768a99af4d888a620eecfbc36576585766e20ad937a4c9
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to websites that appear to be part of a link farm. Several of these URLs lead to compromised WordPress upload storage or are hosted on disposable domains, suggesting a tactic to manipulate search engine rankings or distribute malicious content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://chcial.ru/uplcv?utm_term=how+to+get+back+contacts+after+factory+reset PDF link annotation
    • https://heritagecambodiatravel.com/userfiles/file/nenepafapujag.pdfIn PDF document text
    • http://nayyaralidada.com/alpha/ckfinder/userfiles/files/52569696117.pdfIn PDF document text
    • http://scro.ru/pic/file/1745944643.pdfIn PDF document text
    • http://auto-rad.pl/userfiles/file/549457318.pdfIn PDF document text
    • https://www.nvsrolko.org/ckfinder/userfiles/files/94676266597.pdfIn PDF document text
    • https://strongpointmarketing.net/userfiles/file/diguvixajuxeran.pdfIn PDF document text
    • http://ketoanaca.com/uploads/image/files/jusipuluninetififijonomij.pdfIn PDF document text
    • http://zjhywt.com/images/upload/File/19981185213.pdfIn PDF document text
    • https://sikanderajam.com/Robinson/ckfinder/userfiles/files/51354214176.pdfIn PDF document text
    • https://cplastik.com/data/cms/file/4680200153.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/11618563761.pdfIn PDF document text
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/vasofubedafibalop.pdfIn PDF document text
    • https://xn----8sbcehyodmtf1czh.xn--p1ai/userfiles/file/bixaz.pdfIn PDF document text
    • http://zaintik.org/files/galeria/files/sininaruwidebizadunut.pdfIn PDF document text
    • http://gerd-pollak.de/userfiles/file/74732310375.pdfIn PDF document text
    • http://insfilings.com/skyzone_classic/upload/files/1262488829.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/161320ad5c79d7---tavodikololoxiwewen.pdfIn PDF document text
    • https://grancom.by/upload/docs/mepuwuxowavikejevifipo.pdfIn PDF document text
    • http://lobi.md/userfiles/file/17181358176.pdfIn PDF document text
    • http://holidayservicemarsala.it/userfiles/files/90195414240.pdfIn PDF document text
    • http://salt17.com/userfiles/files/siruki.pdfIn PDF document text
    • http://yas-center.ru/userfiles/file/nisupapumobubu.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419aae0c7ad---zonifikozetome.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613342a01cd45---gerefabobopodawat.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_off0000afa3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFA3 10796 bytes
SHA-256: 4dba078a60ba0d9c4605ed6e6572970cf5a1ba90189085c860d6196b57b6be60
font_01_sfnt_off0000c8c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C5 14500 bytes
SHA-256: 72c87333cecb31d3efbc97d0531e999b6d1b486551ae2fabb5b19b91be82228e
font_02_sfnt_off0000ed1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1