Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6cd8bdecac33446…

MALICIOUS

PDF

88.0 KB Created: 2021-10-06 04:13:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: bc1e33275493227e618c4b140e12fd69 SHA-1: 55768ed1dcc6e9377af9719f667a293302962858 SHA-256: c6cd8bdecac334467efc6be7d2b5b48cb6984f10b1412b6298929fd741c2ae25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, containing numerous URLs pointing to other PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The primary purpose seems to be distributing further malicious content or engaging in SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://autoradiator.mn/uploads/ckfinder/files/21676072054.pdf In PDF document text
    • http://dxline.eu/userfiles/file/81529993635.pdfIn PDF document text
    • https://impactmediaresources.com/userfiles/file/3961169638.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/dae94402b72567b1938bfa07ba53ff06/karudupogubidolajinon.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/mujifinikiduriborur.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1615354dc8e474---bofiwug.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f51ba0e98---genalozubofiza.pdfIn PDF document text
    • http://kielcenoca.pl/files/file/62875442750.pdfIn PDF document text
    • http://wieswioska.pl/userfiles/file/17891058188.pdfIn PDF document text
    • http://sedaciesupravy.sk/media/file/13823496246.pdfIn PDF document text
    • http://hospitalityroyal.com/upload_files/file/panexorudavax.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16130d686bd33d---rujovemubiwakojabedadezuk.pdfIn PDF document text
    • http://ambulatorioveterinarioilprato.eu/userfiles/files/gomajekiduzuzomudib.pdfIn PDF document text
    • https://www.pelicanfinancialnetwork.com/ckfinder/userfiles/files/xudovetobinupasewamaxibi.pdfIn PDF document text
    • https://greenline.bg/userfiles/file/tuwilesogejalomu.pdfIn PDF document text
    • http://noclegsosnowiec.pl/eurostyl/photos/file/44068790322.pdfIn PDF document text
    • http://phrabat.net/UserFiles/File/79955405114.pdfIn PDF document text
    • http://erulingua.hu/uploads/content_files/files/62979362904.pdfIn PDF document text
    • https://radio-aurea.eu/files/file/1097110756.pdfIn PDF document text
    • https://digitaluzaktanegitim.com/calisma2/files/uploads/tizerebixozir.pdfIn PDF document text
    • https://comillaspostgrado.es/userfiles/file/fanavufiniwi.pdfIn PDF document text
    • http://pet.nfe.go.th/m_site/ckfinder/userfiles/files/bovanitonejolala.pdfIn PDF document text
    • https://rjpexport.com/files/jujevuxorav.pdfIn PDF document text
    • http://inarchengineering.it/userfiles/files/wajubozafawivut.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/161381713e5759---wozirusegexira.pdfIn PDF document text
    • https://olivermilk.com/tctt/sites/aaa/file/64974622592.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=geography+english+notes+pdfPDF 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_off0000f0b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B4 10932 bytes
SHA-256: e41c5c567ae63a1867f9d3e66544637500ab2c20bbc861c0d986c427ba4a7da2
font_01_sfnt_off000109cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000121df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121DF 18656 bytes
SHA-256: a6cc8a6ba6ff7d9a74d10c9972222a45060de642f8a3d88a281d425818d1ac4a