Malicious PDF — malware analysis report

Static analysis result for SHA-256 731b661b4d889a85…

MALICIOUS

PDF

98.0 KB Created: 2021-06-26 00:41:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b7d0de493b44fb049fab97f8484d83e6 SHA-1: 0209d5c05777c28a9645c74fab776284d8f01984 SHA-256: 731b661b4d889a858f42c6594eb91d08d564b1b4028399d9755dd56f570840a7
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to phishing or malware distribution sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the classification of this file as a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/0063a4d1cd7234200a1df781fb257f0f/19506056467.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099de85df85d---vavavebivoporigolaroguxu.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b323d8e2221---43635794069.pdf
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/796df5f5ee4ad04a69ab7af44e4e933a/noketibenafivoxuligodatan.pdf
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0217e41b64---xodadawesusufotilazebiki.pdf
    • https://licorne-hotel-restaurant.com/userfiles/file/60577348717.pdf
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/j8uuqj1gk45vburaqsl06h31c2/bevamokewamisaguzobezabu.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607bfbe45b7e3---diravowofizuguzoxom.pdf
    • https://hometeamcorp.com/images/usr/19980820663.pdf
    • http://taxicityplus.ru/userfiles/file/wudenatur.pdf
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608342ab77cb5---sevuvomuvuxejamikawigum.pdf
    • http://alliance-ltd.com/userfiles/53331387079.pdf
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/2vqcap11ihbk620av9qmojqfd7/20545843424.pdf
    • http://ebslang.net/_UploadFile/Images/file/87110183633.pdf
    • https://watfordfairtrade.org/app/webroot/img/files/vewifaxuxamodudij.pdf
    • https://olmitek.by/wp-content/plugins/super-forms/uploads/php/files/5er20f3n55nubrjqo92lkji4i3/37848736376.pdf
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/149rsibskrk7d3eecn89lgtvi1/18544476548.pdf
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160cf9b5822bd3---fitebuxedoru.pdf
    • https://smartmedia.ro/app/webroot/files/userfiles/files/59869685075.pdf
    • http://akkoryazilim.com/userfiles/file/xaxuxeme.pdf
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a4ae074a412---vogetubukabaguk.pdf
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce956111dc---liririkelip.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=buffy+conversations+with+dead+people
    • 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_off00011a49.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A49 16792 bytes
font_01_sfnt_off00013260.bin
1bbccbb65246be60714c4365012374e5c7d5cde51de9bcb4e5d22dbe7668b3a7
pdf-font-stream PDF embedded font (sfnt) at offset 0x13260 11136 bytes
font_02_sfnt_off00014c7a.bin
d0c83ec433161a8a6bd16e2505b66865646908ba2fdf8ab882947a619d8cb106
pdf-font-stream PDF embedded font (sfnt) at offset 0x14C7A 17052 bytes