Malicious PDF — malware analysis report

Static analysis result for SHA-256 efba3c5db155185b…

MALICIOUS

PDF

163.5 KB Created: 2021-08-18 07:36:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f229d3758c05aa7b9f2716dfd13d4b86 SHA-1: 1596ac643667f945d155581e6daa5ad0058c4bc5 SHA-256: efba3c5db155185b8d47b30d1fc0dab028c8b4c7c527934dd28e115b1899f7b4
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, with several heuristics indicating it functions as a link farm. Notably, some links point to compromised WordPress upload storage, suggesting an attempt to leverage these sites for malicious distribution. The ML classifier also flagged this PDF as malicious with high confidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9781

Heuristics 5

  • 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://tinnituskozpont.hu/files/8656226136.pdf
    • https://horacebatten.com/ckfinder/userfiles/files/78940093393.pdf
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16078ba061e7f9---82764207129.pdf
    • https://sts-cct.com/app/webroot/userfiles/files/davulofevukal.pdf
    • http://ewhamd.net/upFiles/ckeditor/files/ponulanejusezu.pdf
    • https://warsztatgdynia.pl/app/webroot/media/files/migutinuboputegipuvi.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/16077aa5344c0c---60917382169.pdf
    • http://uticahighclassof78.com/clients/8/89/89c70e22fe5ad1405280b455f64975d7/File/fegizejutitepotuga.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2ee3b7c3aa---navodizuwogivudinepofax.pdf
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607216c436ac1---44255623454.pdf
    • https://facades-et-traditions.com/actualites/file/gevuwutiwaduj.pdf
    • http://france-ex.com/images/blog//file/tifudofipiwomoxarewiz.pdf
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbdeb25cbdd---26692494485.pdf
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/q5ciemqnc9eqokmr011fh2mof2/12682092708.pdf
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/b9055e4331fe23ab7888bfc32f1fca17/gizusafabewofawizolime.pdf
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/lv0k63p90f0q4pprnd503rdjfs/tezitagefimofarudobasitaz.pdf
    • http://tantex.org/tantex/tantexuserfiles/file/67095724368.pdf
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e256ebbf839---raseposulaz.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/85e3074ad40aca84cbf399fcff4bdc2e/zulilabeworumurifar.pdf
    • http://acm-medicali.it/userfiles/files/mugibebinovider.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/3akab68p57j95acd300h3100t4/89525538345.pdf
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160786206047f9---gobenitijozilutiwiganu.pdf
    • https://ourcampuswindow.com/ckfinder/userfiles/files/jilelifitokuvuguwaloke.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=mahouka+koukou+no+rettousei+light+novel+amazon
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001a94f.bin
ad445218da9bbcc06e1268565d8ee0d93a2ea7908b6e07ba95a1e20ce73e6946
pdf-font-stream PDF embedded font (sfnt) at offset 0x1A94F 18584 bytes
font_01_sfnt_off0001d972.bin
7ee9e2961680ec7fea62e02c62efef7222ac58b6f81909acf7046a2f6331f5da
pdf-font-stream PDF embedded font (sfnt) at offset 0x1D972 10864 bytes
font_02_sfnt_off0001f26e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1F26E 16792 bytes
font_03_sfnt_off00020a7c.bin
70bb409d8991b8ffa054b62dd4e7aae780b3d92be44ed7f0083ce6a5e21fda20
pdf-font-stream PDF embedded font (sfnt) at offset 0x20A7C 41140 bytes