Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dcfe86f977bd499…

MALICIOUS

PDF

84.6 KB Created: 2021-06-28 04:49:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6208ffcd22bd1d85cc3ea7bdc6a5efa6 SHA-1: 3db40fc3c0d16279196738ff512cf1c663477c09 SHA-256: 4dcfe86f977bd4992a71b10782258cf510700c3f5ed82779420794974efec5b2
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier also flagged this PDF as malicious with high confidence. These findings suggest the document is designed to act as a link farm, likely to distribute malware or facilitate phishing by directing users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://kirilmazbardak.com/userfiles/file/20055327382.pdf
    • http://business-plan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/51933015470.pdf
    • http://dok-vo.ru/userfiles/file/86355520111.pdf
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c8f97131ec6---weletanoxeloleta.pdf
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/cd8db6b465742f4495afdddc850b3ffc/xemafowidodugojavuxatib.pdf
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/5fd0f1e30e4e5027a64b8db3f3c866d3/dugok.pdf
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609a8d3ae8640---xamifeguzanabuwiregaz.pdf
    • http://bjhtdszdh.com/v15/Upload/file/202169629157394.pdf
    • http://swaminarayangm.org/userfiles/file/giximitepebagiwu.pdf
    • http://starrsgazette.com/admin/images/file/zojexeguluviguxewadixev.pdf
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/7a033efef2dd5dc1ef04528f44a4aecf/85823613310.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1606f32d6a8ee3---22125804922.pdf
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609220017b6f4---85299425393.pdf
    • http://aire-limpio.com/img/editor/file/rutonunip.pdf
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c3a9404b4eb---28278625453.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160ae1d4568268---89434336336.pdf
    • http://j-club.eu/userfiles/file/sajerevuduvuvamazovogeto.pdf
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/e628a2fa627933c3362b8bbc895fc424/96804754988.pdf
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/42a14e9aaafb3c066ea9f86cc70a05d6/zinobilokutasodavozovegev.pdf
    • https://cardion.dk/gfx/fckimages/file/poberavabe.pdf
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/7f7rqg4ir0po1n44hoha6lp5ma/60650442184.pdf
    • http://albatrossmrn.com/konadnew/userfiles/file/13460785205.pdf
    • http://bvsaigonbinhduong.vn/uploads/files/87215779862.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=cognitive+tradeoff+hypothesis
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e95e.bin
d110565e125bcae295587a7506495c5fc700b1fb25b3b9a6fddd7a746c7aeb55
pdf-font-stream PDF embedded font (sfnt) at offset 0xE95E 10944 bytes
font_01_sfnt_off0001028d.bin
9097f04345fde7387deadf0a26c40e082d847402d8546bc981461204e274db80
pdf-font-stream PDF embedded font (sfnt) at offset 0x1028D 16552 bytes
font_02_sfnt_off00012d4b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D4B 16792 bytes