Malicious PDF — malware analysis report

Static analysis result for SHA-256 da8e36916977e66c…

MALICIOUS

PDF

92.2 KB Created: 2021-09-21 00:09:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 57d069c1ccbf4d1022eee1cead51ddf5 SHA-1: df4531c36d5d109f4e26c70d2fab10c7cfa0fbea SHA-256: da8e36916977e66cf0af83f733f806ccd24509306aab9c7746393705b24fc591
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some URLs pointing to compromised CMS upload directories. The ML classifier strongly suggests malicious intent, likely related to SEO spam or hosting malicious content, and the presence of external URIs points to potential exploitation or redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://ackerviewguesthouse.com/userfiles/file/jewabuwipinu.pdf In PDF document text
    • http://ajitcoatings.com/uploads/wosopatidasule.pdfIn PDF document text
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/37480033670.pdfIn PDF document text
    • http://aotwresort.info/ckfinder/userfiles/files/59707139426.pdfIn PDF document text
    • http://kahasat.cz/data/file/xisoraz.pdfIn PDF document text
    • http://baihsad.com/userfiles/files/20210920_074903.pdfIn PDF document text
    • http://kubablimel.pl/Image/files/tinopabobabexeratemaw.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/16148f6a50acf9---mokaru.pdfIn PDF document text
    • https://eurochen.com/UpFiles/WebEditorFiles/file/31285374631.pdfIn PDF document text
    • http://popmetre.com/news/files/lijatedopus.pdfIn PDF document text
    • http://lukoilmarine.com/ckfinder/userfiles/files/lenupejutefixamebeb.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130655e0dac1---94083152936.pdfIn PDF document text
    • https://corianderedmonton.com/ckfinder/userfiles/files/dufusumasegizititoke.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/161323d744f4c7---nudexolutut.pdfIn PDF document text
    • http://nationshield.ae/userfiles/files/26043156525.pdfIn PDF document text
    • http://ydchem.cn/filespath/files/20210905140038.pdfIn PDF document text
    • https://kisikana.hr/UserFiles/files/bipurisiratosesila.pdfIn PDF document text
    • http://mercuresamuichaweng.com/admin/file/vosomolozalurosibatil.pdfIn PDF document text
    • http://dexgerm.com/data/file/userfiles/files/janisokogijitoj.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/8bb6c17ccc83f4154abf4b7a1a2e7148/50615362054.pdfIn PDF document text
    • http://sh-songshi.com/admin/upimg/file///88457633732.pdfIn PDF document text
    • http://bidadapatidar.com/userfiles/file/rumomifofamemitadefuzi.pdfIn PDF document text
    • https://mahanakhon.pacedev.com/ckupload/files/85860557456.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=android+s%C3%BCr%C3%BCmleri+ve+isimleriPDF 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_off00010394.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10394 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011bab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BAB 10388 bytes
SHA-256: 3f540f70421d04954ad96be2f1f259c328965069bbed417a528a572e5c2fdad1
font_02_sfnt_off0001330f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1330F 18920 bytes
SHA-256: 0c158a03bb6c621c5bcbc26aba3dad7e3d425e173c67128a9bd915011540f470