Malicious PDF — malware analysis report

Static analysis result for SHA-256 11972320d8720c9e…

MALICIOUS

PDF

78.5 KB Created: 2021-08-28 14:42:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 21dd0505f02bdf6e013431d8122b7223 SHA-1: ebfbdf1895cfd188a1b35e2214bb049a21883882 SHA-256: 11972320d8720c9ead2f7936c28caebb83d0c2da24e2747e49ded624b806f297
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, but the link farm structure is a common lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://everest-c.ru/ckfinder/userfiles/files/17789217184.pdf
    • https://khonggiansachhanoi.vn/uploads/files/bibojugaxomegukapedamur.pdf
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160af950b51422---meviwa.pdf
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160926f3b02189---40841472371.pdf
    • https://lesartsdansmonjardin.com/userfiles/file/20210626225104.pdf
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/9f61055e40dc32e3c5d72c27bad54c87/pabasepevej.pdf
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160aae3513f297---60711626182.pdf
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607647a28cd60---mifuniwupuzelesadunasimu.pdf
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fafa93ba23---fujewirisegowum.pdf
    • https://stomatoloska-ordinacija-rijeka.com/files/gatokabuzadimegexixaturu.pdf
    • https://betentour.com/sites/default/files/file/weduko.pdf
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160767ef460b2a---31353735041.pdf
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/fd7871d3d0b987de40f631f1cba45d0d/50285387671.pdf
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b54cc7c52b4---zekivedapemanevapowukip.pdf
    • http://esejsc.com/upload/files/10156500030.pdf
    • http://stark-tools.ru/images/uploaded/13499665752.pdf
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610675ddd342b---jisudikexewik.pdf
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/k752qo2h614idhcsq2g8u0v6ls/51754327403.pdf
    • http://alexandercdg.com/clients/36029/File/segogabovigip.pdf
    • http://schodylux.pl/userfiles/file/fojapamomugatabaraj.pdf
    • http://xingzhongjing.com/userfiles/file/20210820102019_686903432.pdf
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/gkpcsf8ufg0i1rqmem2q3r4341/bemejasu.pdf
    • https://acgroupenterprise.com/userfiles/file/jetanexeteki.pdf
    • http://alnadaoil.com/userfiles/file/10509298189.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/af8f6b242a0ff5adde18f985d7aa8bf1/38702190675.pdf
    • https://perfecthospital.net/FCKeditor/file/9263195797.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=illinois+department+of+education
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/d575209bec2809d4c1bfc5f4d094d01c/78578161666.pdf
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ce9f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE9F 16792 bytes
font_01_sfnt_off0000e6b1.bin
aa6ce6bfa0d1601d14828bbbd6db0d5b6aa475e99ae00a5c12d5a95e9785836c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6B1 16996 bytes
font_02_sfnt_off000112cd.bin
7b2fb3a78790d28ca3251a6b5b1d6a3051196f21c19b931adf2292620863de4e
pdf-font-stream PDF embedded font (sfnt) at offset 0x112CD 10832 bytes