Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c7be67c4e315dbe…

MALICIOUS

PDF

83.0 KB Created: 2021-09-08 18:48:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a8b72ca99b143d020ad7593e221a8f2e SHA-1: 95dd5a7c36edd2b254e9e660174f21ce17d618eb SHA-256: 1c7be67c4e315dbe3f13aea642a1a133e16c3d66dbd8e95550a3c42fd86bf400
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm or phishing lure. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating the document is designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134598689e1b---80533308330.pdf In PDF document text
    • https://by-express.com/upfiles/editor/files/87120800900.pdfIn PDF document text
    • http://altinay-law.com/images/file/poruzor.pdfIn PDF document text
    • http://yetisirkaucuk.com/firma/files/34724482760.pdfIn PDF document text
    • http://roomyab.ir/basefile/roomyabir/files/nakabuvubisutafevodewipaj.pdfIn PDF document text
    • https://ezokniga.com/uploads/file/83143649297.pdfIn PDF document text
    • http://mcap.cz/images/uploadedimages/file/81011426323.pdfIn PDF document text
    • http://snnet.kr/board_pds/fckeditor/2021/09/file/6301198940.pdfIn PDF document text
    • https://grdr.org/paidel/ckfinder/userfiles/files/22450781478.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/10698894333.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/gewidojukabusazorurufex.pdfIn PDF document text
    • http://kanomax-nsk.ru/images/konoxew.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134c6a6da320---60571791593.pdfIn PDF document text
    • http://miryangpension.com/FileData/ckfinder/files/20210901_D334EA01681A07BF.pdfIn PDF document text
    • https://glamweddingdesign.com/userfiles/file/nabetanevozufavufi.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161372919a29cc---sidenepaluxulurup.pdfIn PDF document text
    • http://teakdeck.pl/files/file/padunonejotiluren.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9bc54d279---80245565556.pdfIn PDF document text
    • https://thietbixaydungcantho.com/canthomobile2/public/images/sanpham/files/82531213097.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/204ead468f65056ab65cea083134ec5b/91632176980.pdfIn PDF document text
    • http://ebsenglish.net/_UploadFile/Images/file/61362014777.pdfIn PDF document text
    • http://home-hj.com/up_photo/file/79723914369.pdfIn PDF document text
    • http://paraglider24.de/pics/fotos/1/file/papujosipopilegidosuxuvuj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=latest+supreme+court+judgement+on+498a+pdfPDF 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_off0000def9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF9 17088 bytes
SHA-256: fb72a3c0d867254c52641c85a5d61752c6eeec7bdb91eb7c4c743324f10d9613
font_01_sfnt_off00010adf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ADF 11464 bytes
SHA-256: b4a14e4e2d6605c4e8c0b6667de8e9234d7a289faaec14bb5387874052e51a17
font_02_sfnt_off000125e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1