Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d1055b22ef93692…

MALICIOUS

PDF

83.7 KB Created: 2021-09-17 16:30:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b659b9a66a1adcdd40c744137029355 SHA-1: aab1fb1209f976dbc6788363cff7ba78837ef998 SHA-256: 4d1055b22ef93692c30309f611670f6a3e643128ee3b539cb592c5afaea40811
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and link farm heuristics points towards an attempt to exploit user trust through deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://crysiq.ru/uplcv?utm_term=imo+old+version+apk+file+download
    • http://merwepizza.com/upload/file/6625116221.pdf
    • http://kelkenaghshband.com/app/webroot/img/files/nasonavoliwafixowif.pdf
    • http://cartopack.be/Images/file/80925638263.pdf
    • http://sherwoodchambergolf.com/ckfinder/userfiles/files/96766750285.pdf
    • https://treasurehunterdetectors.solar-ovens.net/ckfinder/userfiles/files/vixutatozil.pdf
    • http://hoteldanang.vn/uploads/images/files/1708248640.pdf
    • http://stlukesfp.org/ckfinder/userfiles/files/66852527992.pdf
    • http://dungcubepgiangtrinh.com/webroot/img/files/53846658731.pdf
    • http://abwcolley.com/uploads/files/30738474447.pdf
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16141564d42251---kimotujumitelagiwotugozal.pdf
    • http://winecellarkeeper.com/ckfinder/userfiles/files/pokaruzi.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/92104548739095799fd5f51801fc5a28/tuxupo.pdf
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/176d52e0ce7959252cd6074b551f7265/85416146465.pdf
    • https://unosms.us/userfiles/file/tajajabuse.pdf
    • http://nyett.hk/uploads/news/files/86924846602.pdf
    • http://abwingssuffolk2.com/uploads/files/40544243743.pdf
    • https://alaskaproauto.net/nbloom/fckuploads/file/kunugo.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/osqtq77oo9du9e2k4fdd6quhq5/95042704931.pdf
    • http://gardens-spa.com/user_pict/file/kutesexe.pdf
    • http://motivationandmomentum.net/ci/userfiles/files/36762909767.pdf
    • https://szabolcsipeter.com/userfiles/file/27967706613.pdf
    • http://studiotipaldo.com/userfiles/files/10046787800.pdf
    • http://udelimpa.es/ckfinder/userfiles/files/4964679586.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_off0000e247.bin
f61d352680cea2823bb0793d9f1e509f3d8cf894ec760286a333c81bf5f44378
pdf-font-stream PDF embedded font (sfnt) at offset 0xE247 17620 bytes
font_01_sfnt_off00010fb0.bin
c9c1c965b59dfafb884fc7a0766072488d97f744119447cb6c0e0daeb42a20e4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FB0 10756 bytes
font_02_sfnt_off00012866.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12866 16792 bytes