Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a40087f4e2a19e7…

MALICIOUS

PDF

87.4 KB Created: 2021-09-07 03:48:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 38dc6c573f93be21ec8f7131f660801c SHA-1: 7dbf39ba80e33686b9899ef36e2541bd9f7ce64f SHA-256: 5a40087f4e2a19e77a872ff74053afac5628765afb848c90464983731187aa8d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous external links, many pointing to compromised WordPress sites, suggesting a phishing or malware distribution scheme. The presence of external URIs and link farms indicates an attempt to redirect the user to malicious content, likely for initial access via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=grammar+worksheets+for+intermediate+level PDF link annotation
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/d87003f3897c7e403fa8d8bebbafb8b1/92606260425.pdfIn PDF document text
    • https://cristalensi.com/public/File/wadudepo.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/160701c863a676---juwafanigewekuworaz.pdfIn PDF document text
    • http://zartmobilia.com/userfiles/file/20210608235620.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607374896cffe---bivaripamusexezu.pdfIn PDF document text
    • http://marinaxaraes.com.br/ckfinder/userfiles/files/67720210318.pdfIn PDF document text
    • http://erdivigado.hu/userkepek/file/vofoko.pdfIn PDF document text
    • http://biosafety.biz/ckfinder/userfiles/files/29145779691.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/b92ba5f4f7cab96f4c9553ef544f60d6/11201644056.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/dcbd607a5a9c8c8c7a62de6b2b44cc8f/xoxalipapinodewapu.pdfIn PDF document text
    • http://lobanowscy.pl/userfiles/file/wuwodalavogud.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c8e7e06bc10---46759913745.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab40e7552d2---54378180184.pdfIn PDF document text
    • https://bloomeng.com/uploads/junopusinakez.pdfIn PDF document text
    • http://schs1968.com/clients/861610/File/98705374414.pdfIn PDF document text
    • https://stiglic.sk/userfiles/file/97787340531.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/16106bef572c5c---pagunezaxunaw.pdfIn PDF document text
    • http://quocteanviet.com/img-chamthi/files/rugurusojoniduf.pdfIn PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/160db8eeea3128---56182958279.pdfIn PDF document text
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160734ca7995e2---fapisizoxalusudirivuv.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/df372a089728a9ad0710f8f5c3ed95ce/27399297179.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160855dfba684b---pamizekipilopiwazarozok.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/436517e1e41885191ba9d1d136b78ce5/wotolidodopirenexod.pdfIn PDF document text
    • https://cowichanmusicfestival.com/userfiles/file/63755177338.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f070.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF070 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010887.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10887 10900 bytes
SHA-256: a158e0ec58b8b883d36e8a76877cc1191f91f08ed4dbde55fcfa41ad4122a9ff
font_02_sfnt_off000121a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121A7 17692 bytes
SHA-256: 68410d2b2cb1df4c0ca9ad7a9bb9793ba10e44079cd5ee7009374be3398bf1ac