Malicious PDF — malware analysis report

Static analysis result for SHA-256 381f1bc9eea37c7e…

MALICIOUS

PDF

73.3 KB Created: 2021-09-05 05:02:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 506e83fb8c4b2cc9de253e661991868c SHA-1: a8214d8aa057ae77ab3f79cd1ff161f77208d702 SHA-256: 381f1bc9eea37c7e29aa26504c5ec7cf2de963710d3b4cd6998ae73ddd3afa36
164 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to external PDFs hosted on various domains, many of which appear to be compromised or disposable, suggesting a link farm designed to distribute malware or lead to phishing sites. The presence of a 'download' button lure further supports this malicious workflow.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://resetimpianti.it/reset/public/file/60081765884.pdf In PDF document text
    • http://acril.ru/ufiles/files/11312379431.pdfIn PDF document text
    • https://quickonboarding.com/wp-content/plugins/super-forms/uploads/php/files/97dabd0b7e666276255cedf9749a5551/32389264029.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/vozexafuzidemuzadeboxadob.pdfIn PDF document text
    • https://nevisnews.com/userfiles/79732210756.pdfIn PDF document text
    • http://interno-kazan.ru/upload/files/72857278353.pdfIn PDF document text
    • http://mackielaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bewed.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607022b809866---97915905757.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/25649956853.pdfIn PDF document text
    • http://udmvdpo.ru/images/files/25187767843.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/tvo13hvdgpa3gdlegt0vba0ahd/bunareguju.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160c2dcf908985---82631061403.pdfIn PDF document text
    • http://wenxuezj.com/images/File/bitukeweku.pdfIn PDF document text
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/pk4gf52olmmu3dgdd4hl83n4ve/66051523076.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/25d4f35d5f562add713a6e6b7844b4fd/13288416191.pdfIn PDF document text
    • https://n-zvuk.ru/upload/file/54409594570.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/bc581f77d33bbe56ece3e2067dba9fc7/97434391130.pdfIn PDF document text
    • http://aucoindeshalles.com/menu/file/48536629108.pdfIn PDF document text
    • http://centralcogtc.com/uploads/file/rijuziver.pdfIn PDF document text
    • http://synergyproperty.com/images/files/lofesudik.pdfIn PDF document text
    • http://netmode.net/app/webroot/uploads/files/79705219397.pdfIn PDF document text
    • http://thamcohoaian.com/webroot/img/files/nijevozara.pdfIn PDF document text
    • http://archi1919.com/smlclub-files/file/94810274300.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fb3ed0b30b---74300438692.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160788631703a6---xigerupubiv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=wings+of+fire+book+1+pdf+free+downloadPDF 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_off0000bc43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC43 16052 bytes
SHA-256: 674e0c581a60156d1d84d22621b71cc2908375da44a9829560e0198125c72955
font_01_sfnt_off0000e5ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fdc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC5 10936 bytes
SHA-256: 1ec4a4710ea11a117869892dcf9385a400c9b8bd9bd7c2fa0e128f59303a19bd