Malicious PDF — malware analysis report

Static analysis result for SHA-256 d850971648836934…

MALICIOUS

PDF

76.5 KB Created: 2021-07-01 10:43:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f16f3055d0841c8330d840f252172405 SHA-1: 03940b2f3811e495515fb72800d0d33fca82da73 SHA-256: d850971648836934d89d00b6be3470c8ea52698b1485b48ac971b7000dd60ba4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress sites or disposable hosting, forming a link farm. This suggests the document's primary purpose is to lure users to external sites, likely for phishing or to download further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://anhuizhkj.com/upload_fck/file/2021-5-30/20210530044400143397.pdf
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/a2dd1357b332acb5b4abd198f8df5646/tijupubakopuzajas.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160838eb386f2e---godajidafitesupiji.pdf
    • https://alianzatours.com/imagenes/file/33697501335.pdf
    • http://brandnewgoods.net/userfiles/file/23035190817.pdf
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087de588ba9e---86150816232.pdf
    • http://ecogestval.com/userfiles/file/ralurab.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d7957aa6224---xurokitifafisovip.pdf
    • https://people11people.gr/uploads/File/ginotunefoziwulazovam.pdf
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607e922f0becb---19513769772.pdf
    • https://andrejc.si/files/file/19945935595.pdf
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/71e58b4595c6eec5f5a3198d1cc99e17/94992459987.pdf
    • https://sfasg.jp/js/ckfinder/userfiles/files/sagitosisigirezexep.pdf
    • http://bptramptour.pl/files/file/1630899780.pdf
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/506de566bd22d1467f7fdbd5d2226857/gebav.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/fv3g6587e9bhev3p33ggj5pnu4/44744878411.pdf
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/160cf10030f828---ropegazupolojovol.pdf
    • http://aydinservis.com/ckfinder/userfiles/files/jugifazexuwuzas.pdf
    • https://ambientltg.com/wp-content/plugins/super-forms/uploads/php/files/976cc7e81c62b48ddcfca209f050336e/23347260878.pdf
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/5f71a81425c410529ff5e1248a9c2723/seweginexonelipobugawunaw.pdf
    • https://calmoinc.com/upload/editor/file/lozofa.pdf
    • http://papinchess.ru/userfiles/file/gupidopuniwuladitazu.pdf
    • https://myphi.biz/nbloom/fckuploads/file/83630829898.pdf
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b37aa058326---mowewebele.pdf
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c867d2d3f16---mozibutezawabe.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e17adb3ea3---ragukafajus.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=pdf+merge+pages+online
    • 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_off0000c9c4.bin
c89b631817983ee02216eaa24c83c85d13898d3d4e8c6e4bf3e53a24737cdc47
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9C4 16408 bytes
font_01_sfnt_off0000f464.bin
dc1337f9452763c26f9e5986a474661f3cf2876a5be39c23dc73ea46839d40b8
pdf-font-stream PDF embedded font (sfnt) at offset 0xF464 10744 bytes
font_02_sfnt_off00010cc9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CC9 16792 bytes