Malicious PDF — malware analysis report

Static analysis result for SHA-256 c52993283248ef85…

MALICIOUS

PDF

77.7 KB Created: 2021-08-01 19:04:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 9a6601efd04aa0d7dfa60acbe53c9161 SHA-1: 2869bb15b17d20c17bb1c2adca3b0ee24a616291 SHA-256: c52993283248ef8547b19f278a90db86540dad5268cf2623c947b5946de4c799
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload directories or are structured as link farms. The ML classifier strongly indicated maliciousness, and the presence of multiple links to potentially untrusted domains suggests an attempt to lure users to external sites. No scripts were extracted, but the document's structure itself serves as the attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 5

  • 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://tapestry.cz/images/file/files/debiwodofojebepumowevoraz.pdf In PDF document text
    • http://ruresept.ru/files/file/18202259232.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/8r6hsf6u44dp6d6ib71lnsvcic/tabaxuf.pdfIn PDF document text
    • http://xn--80aaaaaikdebj9ccf1ayja1b5a3q.xn--p1ai/ckfinder/userfiles/files/mulukodaki.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/sabiruzoxutemosofova.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a9600fee935---69657596875.pdfIn PDF document text
    • https://www.shipgo17.com/plugin/ckeditor/ckfinder/userfiles/files/bavojopoxazojexor.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/765d37f2e83c4e396b98429950357125/varemagomobuwadifap.pdfIn PDF document text
    • http://casaatlantida.com/userfiles/file///pefeduxagalasuwur.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/v205ibc9587equ996ivh6ndke4/75205039869.pdfIn PDF document text
    • http://aweibel.com/Photo/file/43617760825.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/d38994cae488a528239de08cc11191c0/suves.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cfa09f2622a---55254764658.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c6e74db449---36219157873.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/16105b58ef20b6---47550363721.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160ee435712a9e---4088737346.pdfIn PDF document text
    • http://4seasonstours.in/userfiles/file/nemedu.pdfIn PDF document text
    • https://thekolkatapackersmovers.com/ckfinder/userfiles/files/dorevibunirodajes.pdfIn PDF document text
    • http://www.tramag.pl/upload/file/78830727109.pdfIn PDF document text
    • http://geose.ru/userfiles/file/80644039143.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2539477787---xagenajosajoxowesav.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16097348518184---kegewi.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/449ed15ba2aaa65648ff63dacefd14d6/merowujokarafiwaba.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160e4fa686b989---kasex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=zap+suyu+fon+m%C3%BCzi%C4%9Fi+mp3+indirPDF 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_off0000c71f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC71F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF31 18292 bytes
SHA-256: 411941bfcf43ddef7740c261773d261d9ea30d43dfc4390a38ae54fdd465a9ac
font_02_sfnt_off00010c48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C48 11216 bytes
SHA-256: ea1dddce2f32822116e112b585b48f23fac2cd178a9a7748c122fbd36ff8ec1b