Malicious PDF — malware analysis report

Static analysis result for SHA-256 a61d20890f873473…

MALICIOUS

PDF

83.0 KB Created: 2021-09-13 14:22:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 416dfc25c499ee66a3956dfb6b6ee13b SHA-1: 85a6ed10e1dbedce8f1032911c262eb02215890a SHA-256: a61d20890f873473fdd353cbea5226c31b39864ec98509587f3ed41f32bc8706
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised websites or are part of a link farm designed to manipulate search engine rankings. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of compromised CMS upload links suggests an attempt to host malicious content on legitimate but vulnerable sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://celcg.pl/uploaded/file/82833574750.pdf In PDF document text
    • https://www.traitagri-solutions-alternatives.fr/ckfinder/userfiles/files/41452253190.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16130d8ad42f9b---ramerezimu.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/b0suprkotqks4vo43ll2smfp74/38300517331.pdfIn PDF document text
    • http://ladispensadicampagna.it/uploads/assets/file/tilegefilewa.pdfIn PDF document text
    • https://1snrpaulista.com.br/ckfinder/userfiles/files/fejigivepubelakij.pdfIn PDF document text
    • http://fsgpj.com/upfolder/e/files/20210901232644.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/8df322d9022c9309a524cdfb717b0094/42375754714.pdfIn PDF document text
    • https://tongdaidoanhnghiep.com/app/webroot/upload/files/87264125449.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-7/20210907230231855775.pdfIn PDF document text
    • https://tinnituskozpont.hu/files/milawuzixonanok.pdfIn PDF document text
    • https://ajur.rest/uploads/userfiles/file/25906773443.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/272af9rigf0c2sq5heq11lkkm0/34843193750.pdfIn PDF document text
    • http://coachhouse.info/assets/file/95907822975.pdfIn PDF document text
    • http://tuderprogettazione.it/userfiles/files/42753920338.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/16132c83bacd98---tarujadogujekenu.pdfIn PDF document text
    • https://ichibaninfotech.com/ckfinder/userfiles/files/94541307505.pdfIn PDF document text
    • http://immobilieninvestors.de/userfiles/file/53480810300.pdfIn PDF document text
    • http://lucchetta.net/userfiles/files/15292654625.pdfIn PDF document text
    • http://topbondtape.com/uploadss/file/91234599498.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/058424edd0cdd599b78921fd9d3080b0/xupukokukupe.pdfIn PDF document text
    • https://www.soroptimist.be/oldsite/intranet/ckeditor/ckfinder/userfiles/images/files/bujitorowaxenafo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+change+photos+to+sd+cardPDF 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_off0000e201.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE201 10732 bytes
SHA-256: be3e43c62d0731dce5e6bed973c5c1c336cf560499cf88ec7517b1c91250a5fd
font_01_sfnt_off0000fa74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA74 17176 bytes
SHA-256: 4bc69a5222ece3c2e3bfecb1bbdf5d02b6570344874d61b01448cf2d09382c9d
font_02_sfnt_off00012636.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12636 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1