Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5844dba5c019798…

MALICIOUS

PDF

77.5 KB Created: 2021-09-01 19:38:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c92c8e4a9e6f1bfdfa99c0349d4887a1 SHA-1: 2de07f110457cc47712df50d1b2a2b24574ee378 SHA-256: b5844dba5c0197981684ada2435f567547babb8360860f48ffdde8aa14dff278
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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 http://kiavysocina.cz/UserFiles/File/ponemunawe.pdf In PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160e66c27c9b80---motagujigemevexoj.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/cf55fa25b44468e2074412d54e97e66e/8375794871.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/2630149814.pdfIn PDF document text
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/3de0266df0734b47c5dd84109ff83ede/numodesokazutitosana.pdfIn PDF document text
    • http://zetrade.cz/userfiles/file/16362376966.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ada2236d4ea---bakesozumojavi.pdfIn PDF document text
    • http://eca.or.th/ckfinder/userfiles/files/16323873600.pdfIn PDF document text
    • https://majubesar.info/contents//files/67064392432.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/f1aa19b0b94dfa629d06236de9d97e39/86354537890.pdfIn PDF document text
    • http://websteravelandscaping.com/editorData/file/zodisewanezu.pdfIn PDF document text
    • https://toananhmedical.com/uploads/files/13872152975.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b06a26bc62b---5898795380.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160997cb4cd472---zebixupevusazibu.pdfIn PDF document text
    • http://fly.no1-yes.com/userfiles/file/1284267907.pdfIn PDF document text
    • http://anquocrealty.com/uploads/image/files/96257501291.pdfIn PDF document text
    • http://faurau.com/luodan/images/userfiles/file/53451732.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/88473968570.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/75e90d0be026f8d7f9d9f5cbff5e88c8/tumit.pdfIn PDF document text
    • https://vinatech.com/userfiles/file/puredonajuzifutonuraxawe.pdfIn PDF document text
    • http://eviljoy.com/UserFiles/File/bodoxakivenubumebi.pdfIn PDF document text
    • http://finara-v.com/file_media/file_image/file/47029765751.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099895118c80---92348583998.pdfIn PDF document text
    • http://www.multigacos.com/admin/uploaded/fck/file/xawunilumixalug.pdfIn PDF document text
    • https://xn--lenachatka-57b.pl/uploaded/file/mutakoxosaboviluw.pdfIn PDF document text
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/8rvn3quqtkujgvra4fkq0j2536/21473674975.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=cost+of+thar+2020PDF 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_off0000cf43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF43 10212 bytes
SHA-256: 5b2281df31827ba3cfb2b559bb8aee11f004aebc6e7895200aef6a6811c007a7
font_01_sfnt_off0000e65d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65D 16468 bytes
SHA-256: 51d368a7ba79c4c562aa910819319c8b46c70a3f438fd0a949bb20ce4d2b4668
font_02_sfnt_off0001107b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1107B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1