Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bd1b9bfdd592258…

MALICIOUS

PDF

82.2 KB Created: 2021-09-11 21:10:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 10da6e70ee90c186b3f74bb56a8196f2 SHA-1: ad4a0e22003d94ffeb3bd1496b3b0d5595893cf5 SHA-256: 1bd1b9bfdd59225804fedd06d323e6e8dfdba76bfe6cee4163bad268a1739601
96 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting. The ML classifier strongly indicates maliciousness, and the presence of link farm heuristics suggests an attempt to drive traffic to potentially malicious sites. While no scripts were extracted, the structure and URL distribution are indicative of a phishing or redirection campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://praguynakorn.com/praguynakorn/picture/datapro/files/38201366763.pdf In PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/jisujunaja.pdfIn PDF document text
    • http://whatifitspossible.com/ckfinder/userfiles/files/12880989446.pdfIn PDF document text
    • https://at-studio.tw/app/webroot/userfiles/files/20210904_233253.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210901130553.pdfIn PDF document text
    • https://mbzgogo.xyz/web/img/podborky/files/sofunekotojesore.pdfIn PDF document text
    • https://mr-alian.com/upload/ckfinder/files/robamobolak.pdfIn PDF document text
    • https://copyjokertw.aw6.tw/uploadfile/qu4_qu106_com/files/85669877719.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/wininovutuzugexodubi.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbb9e2936a---fekujetedemidat.pdfIn PDF document text
    • http://shipsupply.ru/userfiles/files/41854232820.pdfIn PDF document text
    • https://kcharp.com/ckfinder/userfiles/files/fufewexonokoxekifemexe.pdfIn PDF document text
    • http://kimhoatra.com/upload/fckimagesfile/26780862560.pdfIn PDF document text
    • http://sgrappresentanze.eu/userfiles/files/lorozepidufemalawagap.pdfIn PDF document text
    • http://mptech.vn/ckfinder/userfiles/files/nonelidimuwonafatiju.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161359e1bdb229---68034590041.pdfIn PDF document text
    • http://justsayhi365.com/uploads/file/13638227176.pdfIn PDF document text
    • http://travelsi.ru/ckfinder/userfiles/files/11979272449.pdfIn PDF document text
    • https://democv.associasuite.com/imagenes/contenidos/files/13733076513.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/3fccc709af98853eb34999ecf4ff5c4f/besaferok.pdfIn PDF document text
    • http://danieldesignpro.com/userfiles/6793059905.pdfIn PDF document text
    • http://kapfenberger-schuetzenverein.at/userfiles/file/95301389255.pdfIn PDF document text
    • http://fatename.com/uploads/files/202109061816399376.pdfIn PDF document text
    • http://eros-arena.de/eros/userfiles/file/55512690788.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+dial+private+on+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_off0000de62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE62 17192 bytes
SHA-256: 0ae342d01ff32f55fd0d4b1d29e7e5573faf2a0e49793f9cbbba03b2eb877a42
font_01_sfnt_off00010b68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B68 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001237f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1237F 10360 bytes
SHA-256: 318d349bf4f6ca032f1c08f1b9bcbccc4982c989f29b17c34f4d40a0da545279