Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd4d95844e8e3c42…

MALICIOUS

PDF

84.8 KB Created: 2021-06-25 13:33:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c9dd2a0541abbe3fff3fa0caa7968ff5 SHA-1: bd5b822d960c5ada2687faa9e2d9be25b0d7f443 SHA-256: cd4d95844e8e3c427728f95d064eefc5277d1b5205a4f95c7dc3e79820ebd886
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised or disposable hosting sites. The presence of numerous PDF link farm URLs suggests an attempt to distribute malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://digireg.se/upload/tuvepidasetudipakikuzin.pdf
    • http://cuanhuaabshanquoc.vn/files/sibefekudexifuwebitogej.pdf
    • http://techbis.pl/files/file/28765320360.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16076a74763ba1---gozumox.pdf
    • http://ibshop.gr/uploads/_uploads/files/14970120339.pdf
    • https://northstarexecutivesearch.com/wp-content/plugins/super-forms/uploads/php/files/154a12f1e3d459f35c9ed9e6cb5d3bfa/kosoze.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/94f36e6527525bfc235379b16fa46660/91887187587.pdf
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/004cee18014bea7e01e68c312128d28a/tuxufalogadakabisevipiji.pdf
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/7bajhp44e0f69cebcrvj4679mh/78818712144.pdf
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/1607936bc34473---revevosijinivuwusokuzawiz.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9900324f62---79315612016.pdf
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160cf81c1aced7---8537634960.pdf
    • http://agcslohian.com/userfiles/file/67729982454.pdf
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/4357b611cb1debd7ec8568c92a9ef699/nogukigu.pdf
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/9be2b21167240598f39f101df352e046/74282170523.pdf
    • https://alarrabnews.com/images/content/content/file/vevuwuvepadulexadobavevow.pdf
    • http://nitexprofi.cz/userfiles/file/laduwusezijowux.pdf
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b6e4a730e96---doxudokexupexidufabepozi.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=75+mg+to+g
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d879.bin
362c0475b21a5dba37d3bf65203b926d87119370ababec6b7ad19056efdb1419
pdf-font-stream PDF embedded font (sfnt) at offset 0xD879 9736 bytes
font_01_sfnt_off0000edbe.bin
f7b9253987216832ec511a3c7ffdd777d8ae21bfd21e5a9c2e014f7e310ea55e
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDBE 16192 bytes
font_02_sfnt_off00010374.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10374 16792 bytes
font_03_sfnt_off00011b86.bin
1c5375d495a9213332f351b944e96fe04a30e84f9ea4635b1ce9a372e879bae8
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B86 16496 bytes