Malicious PDF — malware analysis report

Static analysis result for SHA-256 b11d3895fee5d920…

MALICIOUS

PDF

84.8 KB Created: 2021-09-05 09:35:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a7fbc6e561ebb2600e1fc40348bfe035 SHA-1: 811b7919e05da07cdcf64cc645bc845257a1336f SHA-256: b11d3895fee5d9204233ac4932ab9a0f3e2603cb8c5264075611399ca818b73a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised or disposable hosting, indicative of a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the nature of the links, and the presence of external URIs suggests an attempt to lead the user away from the current document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://locum-system.pl/userfiles/file/87748042193.pdf In PDF document text
    • http://auto-spec.ca/fck/file/13909822544.pdfIn PDF document text
    • http://ge-mak.com/files/fakorijajupulepe.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/taruduvuvofitepod.pdfIn PDF document text
    • https://otoform.com/upload/ckfinder/files/86925144950.pdfIn PDF document text
    • http://cokhisah.com/webroot/img/files/1051163494.pdfIn PDF document text
    • http://22vek-omsk.ru/fck_editor_files/files/8414074591.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf58b5969eb---pezavemizaz.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610e9a05b2f6b---waniludibojijobabowejo.pdfIn PDF document text
    • http://otoozevran.com/resimler/files/zulaxuzewakikefexi.pdfIn PDF document text
    • https://hanahana.vn/media/ftp/file/56280806428.pdfIn PDF document text
    • http://findmecakes.com/userfiles/files/xejezozevemugi.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/7okcu54imhfqmrsqvmo85r2umi/86709573106.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160be0f2321cfc---kukarureki.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160728c2b74718---40843735939.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/791edbd335bfe448731be0499aec5f2d/75119304258.pdfIn PDF document text
    • http://ebrinteractive.com/userfiles/file/75893248526.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/linejuv.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/14984318225.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/dca3084c15082fea989fa64ae0e5ad20/teporel.pdfIn PDF document text
    • http://njnccualumni.com/clients/0/05/05b55d2c4c342460da0dc2f503861b12/File/83163518539.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/72752026726.pdfIn PDF document text
    • https://rjpexport.com/files/29194012906.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=shree+mahalaxmi+calendar+2019+pdf+free+downloadPDF link annotation
    • 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_off0000db3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB3C 20836 bytes
SHA-256: da3389da7d472d08c0568174c13143dd7ad596661e8f96dea73b417d7d9a84a4
font_01_sfnt_off00011271.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11271 11344 bytes
SHA-256: 5d9cbde3368221f8b4ff874753b3e490281276586442ad8ce01da57695758f77
font_02_sfnt_off00012d10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D10 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1