Malicious PDF — malware analysis report

Static analysis result for SHA-256 38b1ffecdabe6825…

MALICIOUS

PDF

92.0 KB Created: 2021-09-04 08:37:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7745885f448e88e9ccaf18adefd73afa SHA-1: 918fcbaadcd06bdf74f5061c99fa5768c5871bd6 SHA-256: 38b1ffecdabe6825c52322db2a5fe73681277c3cede9ef7319c2e02c4b727d7d
96 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs pointing to a mix of compromised WordPress sites and disposable domains. Heuristics indicate this is a link farm designed to redirect users, likely to phishing pages or to download further malicious content. The ML classifier strongly supports the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://inwebjor.ru/uplcv?utm_term=historia+clinica+completa+pdf PDF link annotation
    • http://szao-spb.ru/images/news/file/vabeziwotaw.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ecb5856b6---xijaxakamatez.pdfIn PDF document text
    • https://vinadesigndanang.vn/uploads/image/files/lojisilegosinuleradar.pdfIn PDF document text
    • https://advance-pack.com/editor_upload/file/89126815206.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/45188184093.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607c22fa5f636---pavanebesapubupobaw.pdfIn PDF document text
    • https://taipeitccia.org/CKEdit/upload/files/rizugegolomanozejufosax.pdfIn PDF document text
    • http://aitrans.cn/UploadFile/file/F1202107160310344539.pdfIn PDF document text
    • http://jhdljz.com/userfiles/file/1630505565.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160faf27e2a885---fixovilunurado.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160bd637090be1---42460162519.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a241831982c---51550779227.pdfIn PDF document text
    • http://sbsinternationalschool.org/sbsisnew/userfiles/file/fogozuwepipuzajulox.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/q183s2sim4l3mik6f2a44cdtgd/94111147435.pdfIn PDF document text
    • http://atomleasing.ru/media/File/74188522314.pdfIn PDF document text
    • http://istihdamhaberleri.com/upload/ckfinder/files/13909291464.pdfIn PDF document text
    • http://purpledoorchurch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079cb261cdbf---27075156758.pdfIn PDF document text
    • http://jobsandhi.com/uploaded_files/userfiles/files/77961889284.pdfIn PDF document text
    • http://cmrivestimenti.com/userfiles/files/jokebazixoxatupomajeb.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/0ebba87434968e58a1a1c6f69b174a5d/kuzipufinenidukilis.pdfIn PDF document text
    • http://serramentisiciliano.it/userfiles/files/758335001.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_off0000fdc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000115dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115DD 10772 bytes
SHA-256: 13b6490f74d1ce52d8d49dcce46bfe3af5eba746aa98a8d4650558cbc118c62c
font_02_sfnt_off00012e93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E93 19720 bytes
SHA-256: 42c941659b6038225a936e1b2ca903cebf185b212c9fd9325dcc4ca6ba1fa447