Malicious PDF — malware analysis report

Static analysis result for SHA-256 40ff852a5e0ac3b7…

MALICIOUS

PDF

73.2 KB Created: 2021-09-26 11:52:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4166d6c9ed1440c7e5d80cb6fca8ba6 SHA-1: b271b7d16637a9580c97e9e8348043066c8e2277 SHA-256: 40ff852a5e0ac3b76041d4dbf320778ef6fe1aa44ba4fa3307ec2166eed79567
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to phishing or malware distribution sites. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

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 https://inwebjor.ru/uplcv?utm_term=get+likes+%26+followers+free+2019
    • http://ozdoby-betonowe21.pl/Upload/file/kudumozu.pdf
    • http://runbo.net/upfiles/files/16319601603402.pdf
    • http://yyfxsw.com/upload/files/nezamemezatenu.pdf
    • http://kebirbeton.com/userfiles/file/vegujixife.pdf
    • https://oncetrabzon.com/resimler/files/92870110676.pdf
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/ff296b7bf45872c9904828b3b53341d9/kanegosaxewafavuva.pdf
    • http://graviroz.hu/ckfinder/userfiles/files/nitotevawe.pdf
    • https://muratay.nl/userfiles/file/monuxepixel.pdf
    • http://ducthanggroup.com/webroot/img/files/digesuvetin.pdf
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/bt0ti2qaju1h74gj6ldi0qsqrs/mumuka.pdf
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/62583152214.pdf
    • http://hkacca.com/userfiles/38022073554.pdf
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613987d91da82---xepukosasatudazilirunoje.pdf
    • http://defhjdr.friend-match.com/upload/files/doridumo.pdf
    • http://sevimticaret.net/userfiles/file/81281757098.pdf
    • http://abwingsbuffalo.com/uploads/files/mowakuborujunegodizuxevo.pdf
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/jivanesap.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/tch62isjucs3hn4c98oi578jne/24937936281.pdf
    • https://rosebankprimary.co.za/inc/ckfinder/userfiles/files/85610046279.pdf
    • http://geose.ru/userfiles/file/86906917818.pdf
    • http://twsl.mingann.info/upload/ckfinder_temp/files/20210915095726.pdf
    • http://papierplus.pl/userfiles/file/futegazevuxikagamiruso.pdf
    • http://www.portofmiamitunnel.com/system/js/back/ckfinder/userfiles/files/nimuxedufub.pdf
    • http://chataphan.com/file_media/file_image/file/zoler.pdf
    • http://kokocurry.gm/userfiles/file/benonadaribabetubebip.pdf
    • https://777mto.net/contents/files/jiziwawemodujepawuwed.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_off0000b89a.bin
6979741d536c135f9c4eab38e0b793dcaf87400b957cc5a705957f2d460eff15
pdf-font-stream PDF embedded font (sfnt) at offset 0xB89A 9744 bytes
font_01_sfnt_off0000ce05.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE05 16792 bytes
font_02_sfnt_off0000e617.bin
dcbac7e6f7fe60b9a7752b85321132677177b69dca1cc44045081d81cc46de57
pdf-font-stream PDF embedded font (sfnt) at offset 0xE617 19564 bytes