Malicious PDF — malware analysis report

Static analysis result for SHA-256 b44a6ab9e06df5ad…

MALICIOUS

PDF

88.8 KB Created: 2021-07-17 14:00:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2157c1e83413ff779f020f7d5847372b SHA-1: c9071239d5247feb0f35423134cbfa7452ef8d89 SHA-256: b44a6ab9e06df5ade9416d12b610782a8a9ee4872463c30e610ad032dca67dd9
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. The document body is unreadable, but the link farm structure and heuristic firings are sufficient to assess its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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://legacyltg.com/wp-content/plugins/super-forms/uploads/php/files/5f2faa28dabf9ef36e0c2f5dc41d0d33/xolebo.pdf In PDF document text
    • http://nuraski.pl/wsg/userfiles/64152453970.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/88470883746.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/119448234160aad829dab6e.pdfIn PDF document text
    • https://bawaniint.com/ckfinder/userfiles/files/nugavak.pdfIn PDF document text
    • http://jrmhandling.nl/upload/file/53099808044.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/89783edf3e7a0a25fd48ae0bd2523de3/19793538087.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160904dc6d437b---41075798039.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b0c9591a0d5---52447226238.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6ac17ab093---72043104336.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/6g3uujk582321tn32jlnqlail2/36615954762.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/d2bb6e7b4fe8eef0c197edcb057aee10/buwuxedagovezal.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a758fe716a7---30648802512.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/bcc5a4398753f3aa0d6b81254f29a5b8/65711314846.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/79mu74a64hbr1jcbbhotfn3aik/zorugifubadonuv.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b63ac4f38ed---94226305109.pdfIn PDF document text
    • http://93564497.com/userfiles/kelogunobivafoxo.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd629dcae6---juvijaveperekewuranaveto.pdfIn PDF document text
    • https://aadharshilaschool.org/userfiles/file/54068168198.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/0c93eab8c0b956560fe6325680bf4c1c/4227357316.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/c269c9bb3bae46001cc8931c72cbccf5/96180160085.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606f409a6a61b---buziweva.pdfIn PDF document text
    • http://medrea.ru/upload/files/nitateroleterusimujewiw.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ab5d40317fa---48562721767.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/2d5ca74d8849aa89eea440ba033745db/89668395530.pdfIn PDF document text
    • http://theettiaresmontreal.com/clients/f/f0/f03dfc1790708d0b03c48e9879ef2ea6/File/26228354796.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160c514f1dc0d7---72914938369.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=i+know+whom+i+have+believed+scripturePDF 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_off0000f37e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF37E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B95 11216 bytes
SHA-256: d1c846c21e50638bb01ccd7b984d05d4c831bb486e082fa520737b46875d6300
font_02_sfnt_off0001256e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1256E 17776 bytes
SHA-256: 21d60eb2add25ba47de363a0d3b39acd1b186e691a660f9ca9d5e42f7b73c28f