Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8b8d506d6a87a30…

MALICIOUS

PDF

73.6 KB Created: 2021-09-25 15:07:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1e052b5aac8b4fccb77270a68c251c99 SHA-1: 6eebdca994bd65d155734cf91af109b105c305c4 SHA-256: f8b8d506d6a87a30b84d81c7634e5f403a6babd1b4e2e2bb02cc86bd146d95a2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URIs and links to compromised WordPress upload storage, suggesting it functions as a link farm to distribute further malicious content or phish users. The presence of multiple PDF link farm heuristics reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9940

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://krisoc.ru/uplcv?utm_term=smash+flash+games PDF link annotation
    • http://restokrat.info/userfiles/file/xexamerevo.pdfIn PDF document text
    • https://web-dev.ethioapp.com/websites/lightyearsahead/code/userfiles/files/21901191867.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/bataja.pdfIn PDF document text
    • https://charming-dc.com/uploads/files/202108311725568401.pdfIn PDF document text
    • http://anquocrealty.com/uploads/image/files/denawete.pdfIn PDF document text
    • http://mirsistem.com/depo/sayfaresim/file/18341496237.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/69a62981a14377a7007135862f509a29/motupezine.pdfIn PDF document text
    • http://ontozescentrum.hu/tmp/1578074191.pdfIn PDF document text
    • http://elesi.eu/fichiers/files/ginop.pdfIn PDF document text
    • https://apteka-wratislavia.pl/halatecza/userfiles/file/jofarakobezekiguvuj.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16148ad4c0eda5---52119602078.pdfIn PDF document text
    • http://xn--aknmedical-yub.com/uploads/file/ladakiv.pdfIn PDF document text
    • http://wtmongolia.com/materials/file/tumowapokulipojivek.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16145ce7629bac---62136835151.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/161472af7aacd0---burowovafimo.pdfIn PDF document text
    • https://www.eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/tonitirepemobifuji.pdfIn PDF document text
    • http://hferrynetworks.com/FileData/ckfinder/files/20210915_903B8B1C517C9CEE.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/29717585411.pdfIn PDF document text
    • http://saveursetsavoirs.fr/image/file/83155840701.pdfIn PDF document text
    • https://gamepinleri.net/calisma2/files/uploads/namifo.pdfIn PDF document text
    • http://synfarm.com/upload/files/84964250315.pdfIn PDF document text
    • http://newkontakt.ru/userfiles/images/file/povamozoximidimiserivir.pdfIn PDF document text
    • http://hotelgiottotorino.com/userfiles/files/kuxagul.pdfIn PDF document text
    • https://clubelsendero.com/img_pag/file/satilexofifokosipika.pdfIn PDF document text
    • http://nocleginaplus.pl/uploads/userfiles/files/6368934657.pdfIn PDF document text
    • https://citronel.com/userfiles/files/temezifekazufogawoxud.pdfIn PDF document text
    • 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_off0000b9a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9A2 18872 bytes
SHA-256: 3c70e5ad6a616823756787cde991920f7116c7c406b91e83194a082cd89177f7
font_01_sfnt_off0000e9a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A7 10220 bytes
SHA-256: 119179705663e9c4088c9e2dc714eac2e019a3d0fd66c0e63eb18bdff1b867ee
font_02_sfnt_off00010092.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10092 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1