Malicious PDF — malware analysis report

Static analysis result for SHA-256 7417f530373e0669…

MALICIOUS

PDF

87.0 KB Created: 2021-09-19 10:18:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: acdcb49dd42d111ef0cbceeda8dbb782 SHA-1: d189775ca45e998ca527ccf8f6a51e718294976c SHA-256: 7417f530373e0669f0c19cd017d663fa70332c7200a508740241c510c1f3f7f1
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which are associated with compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is intended for malicious redirection. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://synerhu.ru/uplcv?utm_term=client+server+android+app PDF link annotation
    • http://matchonusa.com/uploads/files/97530745626.pdfIn PDF document text
    • http://studiolegaletrotta.eu/userfiles/files/tasinibufutoduwaka.pdfIn PDF document text
    • http://aow.infogestnet.it/ckfinder/userfiles/files/lizafiwosapolalu.pdfIn PDF document text
    • http://oio.cn/uploadfiles/files/39079871542.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612edd075fca8---fudewukokim.pdfIn PDF document text
    • http://togclick.com/media/userFckfiles/file/58764560851.pdfIn PDF document text
    • http://anthonyjcincottalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89736178678.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/68501894409.pdfIn PDF document text
    • http://patanjali.zohukum.com/ckfinder/userfiles/files/finowituxij.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16144b93105a48---mewuviw.pdfIn PDF document text
    • https://baptistfriends.org/media/kebuzopas.pdfIn PDF document text
    • http://pop-around.com/file_media/file_image/file/gubana.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/rojivi.pdfIn PDF document text
    • http://traviet36.com/upload/files/wotevabarijopazovuwu.pdfIn PDF document text
    • http://www.radanhorse.com/resource/files/7022669939.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///basizawikumupajejuruveg.pdfIn PDF document text
    • http://www.moyekolodin.com/files/39721315786.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/0997f2312aa5cc3624abbfa9579906fd/toxamironarisugijozek.pdfIn PDF document text
    • https://satellietgroep.nl/userfiles/files/18623016738.pdfIn PDF document text
    • https://rivieresoceanie.com/ckfinder/userfiles/files/67890850209.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16137a5bee22db---nalopol.pdfIn PDF document text
    • https://benhgout.net/uploads/Files/file/91619292000.pdfIn PDF document text
    • https://rmp-traueranzeigen.de/cms/files/1877665324.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/6960040522.pdfIn PDF document text
    • https://sjamsul-hidajat.id/ck_uploads/uploads/files/97293391901.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_off0000efc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC9 17872 bytes
SHA-256: 7cc7fb7fcd27cbbb2076b8ece060035e81f0baf9bbb2abea2a804256d39b56ed
font_01_sfnt_off00011e9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E9F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000136b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136B6 10480 bytes
SHA-256: d1020bfcb8e9fcd6f36b17deba335ee8ccdf4301e2677c23e44238145e4ca6c8