Malicious PDF — malware analysis report

Static analysis result for SHA-256 99dbf504e4820e00…

MALICIOUS

PDF

86.8 KB Created: 2021-10-05 08:30:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 76fc6d1b4324818272c2df146009ce16 SHA-1: 467cb810ef61c1fe84f16c24d39426e9777d3179 SHA-256: 99dbf504e4820e00f52b3544dbbba15e4f591393c06484b2abd4ddec3f1a8259
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to disposable hosting or compromised WordPress sites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards an attempt to lure users to malicious external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://synerhu.ru/uplcv?utm_term=kitchen+remodel+mistakes PDF link annotation
    • http://gmkms.net/upfile_editor/2021/files/mulaziwugijigilekijo.pdfIn PDF document text
    • http://dakmet.pl/upload/xigure.pdfIn PDF document text
    • https://muacash.com/webroot/img/files/26407621880.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/161589a67876f6---251587759.pdfIn PDF document text
    • https://woft-dining.com/webroot/editor-uploads/files/61157379544.pdfIn PDF document text
    • http://rpsbchamber.org/editorData/file/jufifuluporimebusajimu.pdfIn PDF document text
    • http://acelybio.com/upload/files/65526240867.pdfIn PDF document text
    • http://emaaravm.net/upload/files/wiwijevawafinamubaxew.pdfIn PDF document text
    • http://zatoodesign.com/userfiles/files/mevejobowagixisegakaxutup.pdfIn PDF document text
    • http://www.77ice.com/upload/files/47956286659.pdfIn PDF document text
    • https://nvsrolko.org/ckfinder/userfiles/files/90659765285.pdfIn PDF document text
    • https://prolocolidodisavio.org/ckfinder/userfiles/files/13328742359.pdfIn PDF document text
    • https://playindiano1.in/ckfinder/userfiles/files/mulafevadaxuwo.pdfIn PDF document text
    • http://ski-experience-japan.com/images/blog/file/memidejemepuronujizabuzi.pdfIn PDF document text
    • http://anticacarsulaeborzoi.eu/userfiles/files/51721881159.pdfIn PDF document text
    • http://faurerom.com/userfiles/file/82665949144.pdfIn PDF document text
    • http://yeongwonenc.com/userfiles/file/57508733226.pdfIn PDF document text
    • https://thietbigas.net/media/files/57759909501.pdfIn PDF document text
    • http://analhospital.net/file/files/timifarafoxuzu.pdfIn PDF document text
    • https://officialbacknumber.org/editor_up/mexafutib.pdfIn PDF document text
    • http://liderzy.natura2000.pl/imgturysta/files/vudadav.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/b88a30c350b181393bb1d7a8ebeaf26b/pizemurasemosira.pdfIn PDF document text
    • http://verynailscm.com/user_img/file/wewematevutirimosud.pdfIn PDF document text
    • http://fandimnarodaku.cz/upload/file/saxepinojupuzezipapinape.pdfIn PDF document text
    • http://decaiyun.com/upload/file/21091114525263788817464gy9gexg.pdfIn PDF document text
    • http://thietkewebbacninh.com/webroot/img/files/79583631392.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/3bef6a6fd76df5335d46645bd6a6e6eb/pujerofe.pdfIn PDF document text
    • https://b2cdemo.tickets.com/content/files/gazumogelib.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_off0000e9ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9AE 19840 bytes
SHA-256: 00e27c45f8e2cd6f8d49a8a4980dc567b80d22e434a2aa1eacf45de1fb6b1856
font_01_sfnt_off00011c73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C73 10716 bytes
SHA-256: 24a06ddc4e33c26e5bfd46f37b035840644709159fef645db4a9425c149d5928
font_02_sfnt_off000134de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1