Malicious PDF — malware analysis report

Static analysis result for SHA-256 43435cdc82ae41d7…

MALICIOUS

PDF

70.4 KB Created: 2021-06-14 13:44:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: b20b98f05dfc2b94e010bb70f51304ff SHA-1: faff8a9bb04cf098c46c663b0a10a35915c4fbec SHA-256: 43435cdc82ae41d744cd8ef888bad409b21ceb8ab687267016751e559523473f
164 Risk Score

Malware Insights

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

The PDF contains multiple links pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading malware disguised as free stickers. No scripts were extracted, but the overall structure and URL findings point to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://laborke.ru/uplcv?utm_term=free+printable+aesthetic+stickers PDF link annotation
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160710be72cfb7---80288800628.pdfIn PDF document text
    • http://www.siscbolivia.com/admin/uploaded/fck/file/83476228793.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/8cbbe1abdd466852fbadf14aafa89cde/61033071928.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160873a23197b7---5954426195.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/60648c203a8982f4fb2bc5ef9cc58cd5/rodapokerigutazokapojamum.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/omptckghb1ammf3gm1uhscmk62/dewatijevokoxeber.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/83607238332.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607f16e6d90aa---49849331316.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/33b8b3ee8ce30e56071a5f1573007cae/xewuvuxosujujofabom.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/abe56cf1abbec7686c135a5a4854c7d2/91876720542.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16085c35a1f054---59688059806.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16095f91586c87---pemetemulutijapopogav.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6B8 5180 bytes
SHA-256: 4d70838bf5dd94a1c89dd3b6c74d5bfd7c3a74f8f486784ec848cebb189e601e
font_01_sfnt_off0000e84c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE84C 10824 bytes
SHA-256: 663d8ca847cc4390435f9a6679c79a575bc8730c3cce197a3f2bdd7a6927e4fe