Malicious PDF — malware analysis report

Static analysis result for SHA-256 e231eac30bf5e5da…

MALICIOUS

PDF

72.5 KB Created: 2021-09-08 05:01:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 19e7932987af2f452b1d155fd5ca10af SHA-1: a6bff3ca90073734e339f96e42d6d0d390f0ac3a SHA-256: e231eac30bf5e5da9f9d87a4dbfc6bfa5a2fc9b352deb31669eb5e7dc4e25e36
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to other PDF files hosted on various domains, many of which appear to be compromised CMS upload directories. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to lead users to potentially malicious content, possibly for phishing or malware delivery. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • 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://coretry.ru/uplcv?utm_term=article+370+pdf+download PDF link annotation
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/e48debc18d1b533d09fafcfdadfcaf61/73637775177.pdfIn PDF document text
    • http://dentalweek.eu/userfiles/files/28778863720.pdfIn PDF document text
    • http://pc-driver.ru/userfiles/files/40394191533.pdfIn PDF document text
    • http://kondicionery-vidnoe.ru/upload_picture/file/rumilarevorazudug.pdfIn PDF document text
    • http://k12kos.com/ckfinder/userfiles/files/55503751923.pdfIn PDF document text
    • http://sbcnepal.com/images/file/56540324592.pdfIn PDF document text
    • http://asijskepotraviny.cz/files/file/34435551518.pdfIn PDF document text
    • https://medtek.vn/storage/file/vunuzilumawilarid.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b6dbe98306b---25342337196.pdfIn PDF document text
    • http://hytechplus.com/userfiles/file/79066687219.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c8995ca3b7a---68149741096.pdfIn PDF document text
    • https://repare-ton-smartphone.com/userfiles/file/15161953278.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/17422131364.pdfIn PDF document text
    • http://kkitv.com/images/upload/File/94932361746.pdfIn PDF document text
    • https://longhoang.vn/upload/files/lijofufawab.pdfIn PDF document text
    • https://aalatour.com/basefile/b2caalatourcom/files/petag.pdfIn PDF document text
    • http://hnkingdee.cn/Files/file/20219333626.pdfIn PDF document text
    • https://dodatnojamstvo.com/userfiles/file/80809724309.pdfIn PDF document text
    • https://rowanmkt.com/Uploads/ckfinder/userfiles/files/56623489117.pdfIn PDF document text
    • http://retailcop.ca/files/fofijizu.pdfIn PDF document text
    • http://tokyoracing.hu/userfiles/file/mafugawinevosedelokozub.pdfIn PDF document text
    • http://villahetzwartepaard.nl/survey/userfiles/files/jovobefixivovigomum.pdfIn PDF document text
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/85385d51ecd978fd1efd3560278e72bb/68265984052.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/nkqrod875iamq64nj80tc84s3q/59718178876.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_off0000b5d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cdee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDEE 10856 bytes
SHA-256: 9ccc0d67da0c0e8fc72b971f7edea55046a24e1c3a62ea88d490a181ea000580
font_02_sfnt_off0000e742.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE742 17632 bytes
SHA-256: f5f41c438fccba38b977bdeb1bf0da1390ca2701aa25c2a50458b7412d2339b3