Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4acd1dba5c9398e…

MALICIOUS

PDF

85.3 KB Created: 2021-08-26 12:22:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2217aa629fad7054b4443046d5e362c0 SHA-1: cbda24ce6a038aba889f5e55f0b2e41bc50bf9fd SHA-256: c4acd1dba5c9398e004077f51be584419b2c7b494ffa9142f360cf95b9a760e5
96 Risk Score

Malware Insights

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

The PDF contains a large number of external URIs, many of which point to compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the link farm structure suggests an attempt to redirect users to potentially malicious content or phishing pages. No scripts were extracted, but the overall structure and URL distribution are indicative of a malicious campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://wastran.ru/uplcv?utm_term=networth+immigration+solutions PDF link annotation
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/5ml2l3ipnbb5c6hgigoq04lvj7/jamiligojare.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce8cf661e9---93825756375.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16082bcdf4fe65---pirogijawogizixewejo.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/d739a41898832dabcf02c2e784931f9e/2654630464.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce07ba56fd9---80447799197.pdfIn PDF document text
    • http://imi.vc/upload/files/goxow.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021061710512569.pdfIn PDF document text
    • https://buyafranchise.org/files/files/81217795572.pdfIn PDF document text
    • https://dubigroup.com/admin/fckeditor/editor/filemanager/connectors/upload/file/detumeselu.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161029629c1951---xubumawofukodob.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee31da4f63---91769061041.pdfIn PDF document text
    • https://vestol.bg/files/file/81480300204.pdfIn PDF document text
    • https://iamtimeshare.com/userfiles/file/62504216199.pdfIn PDF document text
    • http://www.leposeur.fr/site/upload/ckfinder/files/2178206017.pdfIn PDF document text
    • https://crpm.ch/ck/ckfinder/userfiles/files/78443673595.pdfIn PDF document text
    • http://dambi.pl/userfiles/file/98847775855.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2007638ed---bibewelajamesilefodewezis.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077ea564a5b8---83164994832.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160d931116cfe0---27062860007.pdfIn PDF document text
    • http://zuche0551.com/upload/file/10609959404.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/7161607412.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bba60cd0b43---lamasegiwikiwokuvesevonam.pdfIn PDF document text
    • https://marathonroller.com/userfiles/files/zofud.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_off0000e80d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE80D 17420 bytes
SHA-256: 0a62b0c72db9a2d6ecf148a77bc084c09e56b1e1f5750699305f535a7fd4802d
font_01_sfnt_off000115b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012dcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DCF 10716 bytes
SHA-256: dac2d711fb40e7e5713f73df3bffe98a2395f22fc7695ec7ea8637d4c2d446d6