Malicious PDF — malware analysis report

Static analysis result for SHA-256 811b4f29577ed3d8…

MALICIOUS

PDF

107.0 KB Created: 2021-06-29 17:21:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8a1705b28b8db78b0523effcf8a3afa5 SHA-1: fc9aa747dd3f0e0522a55b76c0c8821c69346876 SHA-256: 811b4f29577ed3d807e380f02a064c07df628f920b17f73e92a301a07d50b5ce
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as a phishing trojan. It contains a large number of embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of external URI heuristics and the ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9797

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://ketchas.ru/uplcv?utm_term=the+boundary+lines+of+congressional+districts+must+be+redrawn+every+10+years+to
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16082565735336---kerirexiludurazer.pdf
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c87181962ef---13538090991.pdf
    • https://brahmagnanam.org/fck_uploads/file/53153395753.pdf
    • http://collegium-connect.nl/ckupload/files/86513336430.pdf
    • http://kasystemofkarate.com/clients/861259/File/fudurarurozanewaki.pdf
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/135809322e01cbf2c1a02d911380a375/58031555925.pdf
    • http://vencedor.coop/images/admin/file/37127168912.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/d557a9rvigf1dmm9pumcrno4m1/30884548207.pdf
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/bd852cb35bd420cfd3f33be0fbb562ac/nadekanovu.pdf
    • http://worthingtonpark101.com/userimages/88053924579.pdf
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609ed4b7c051d---semudokewibilatopo.pdf
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c683215daf---84704756161.pdf
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/10e3040ee8db8cbd409d23d4c2833184/21819788071.pdf
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/gakq0opco1e8m6rjlt67n0tk83/vuxovukimoxot.pdf
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/aee5d309c350dc0f561b47758749c66d/2563113024.pdf
    • http://cedule-plachty.cz/files/file/71788366479.pdf
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078e997f2176---nizimupux.pdf
    • http://fogathajtohirek.hu/fckfiles/file/14204674585.pdf
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/f35a66c18148e7e5aa931d1563e5bb83/razabefojonaluvaxen.pdf
    • https://uleiuri.ro/userfiles/file/xafizojitarulopuvol.pdf
    • http://makinsushi.com/uploads/files/bukasobugidudaperifatezeg.pdf
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160ac133150334---50102648211.pdf
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/gurs8mpdrbds4nv3tqe26iaer1/22689402026.pdf
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/5s6438if0kv3pmj3fl3ntrok96/bevetodexalame.pdf
    • http://aitrans.cn/UploadFile/file/F1202106190247458453.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160c2632ea2364---detaduvunadaz.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_off0001398d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1398D 16792 bytes
font_01_sfnt_off000151a4.bin
fb1a315bd1ebd2c52e76565da2b4e361abb94712578391dd038080d43fdfb38a
pdf-font-stream PDF embedded font (sfnt) at offset 0x151A4 11564 bytes
font_02_sfnt_off00016ccd.bin
717af6d1fe799b3bcd3f367bce2ec079b31dcf454e7076cfb65691045b56dc39
pdf-font-stream PDF embedded font (sfnt) at offset 0x16CCD 18988 bytes