Malicious PDF — malware analysis report

Static analysis result for SHA-256 13ab5913af828a7c…

MALICIOUS

PDF

81.7 KB Created: 2021-09-03 17:29:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 37930cb27bc104831ffc1d98b1dcceec SHA-1: a4e1007c964ac22598e0d9ac6ce7930942447517 SHA-256: 13ab5913af828a7cd27f08063c01acaa4934d085e9310a706ae1db9582657d4f
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which are hosted on compromised WordPress installations. This structure suggests the PDF is designed to act as a link farm, potentially for phishing attacks or to distribute further malware. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://www.swissfillon.com/wp-content/plugins/super-forms/uploads/php/files/c7289446bbb734c090d52a7b26a3ca0d/nizavijipiganamu.pdf In PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/c84d35bbf5aa0ba16c253009385d3a08/1173067927.pdfIn PDF document text
    • http://z500.si/files/zesusaxanuzado.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/gajijowixobemutizur.pdfIn PDF document text
    • https://mecaniquekd.ca/upload/file/51886859203.pdfIn PDF document text
    • http://bayernglobal.de/userVZ//file/19650448195.pdfIn PDF document text
    • http://vinabomi.com/uploads/userfiles/file/remox.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/c6d6682f94ddb3d4f5eb8fc4a4f26d1e/54150153277.pdfIn PDF document text
    • http://regimhotelierbucuresti.com/images/userfiles/miwaf.pdfIn PDF document text
    • http://mckeoughfamilyreunion2021.com/clients/b/ba/baf9e6b347377fae0abe5a87436fc4cf/File/pamonemulijewatitux.pdfIn PDF document text
    • http://digifast.cz/userfiles/1992093119.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd386784f03---52476481519.pdfIn PDF document text
    • http://lauraestetica.com/userfiles/files/86215548864.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d48e561e5c3---jawov.pdfIn PDF document text
    • https://tagoproperties.com/ckfinder/userfiles/files/38205478516.pdfIn PDF document text
    • https://bonafideonline.com.ar/wp-content/plugins/super-forms/uploads/php/files/fcf9164e063f68db7e38fb1936cefca1/libetofetozaf.pdfIn PDF document text
    • http://m-camper.ru/ckfinder/userfiles/files/92414143555.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16093b4c974d48---24096027238.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/6a80a3957a732d62d4f463ea6c355da0/71172342732.pdfIn PDF document text
    • http://dream-mebel.com/pic/file/1525476130.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/g1kq3vgcjsqdnp259tmcfhl1d3/ragofure.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae803bdae84---kokene.pdfIn PDF document text
    • https://atcotourismtravel.com/userfiles/file/65922058442.pdfIn PDF document text
    • http://minhvuongthuphap.com/upload/ck/files/89252023796.pdfIn PDF document text
    • http://atlonnuri.org/UpLoadImage/editer/files/5726142179.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=crio+9040+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_off0000cea5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEA5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6BC 10180 bytes
SHA-256: e7b4e33dabf5265eb3c38ce6d8860ca0f6828380db2691b4ffe2e492f461f81e
font_02_sfnt_off0000fd99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD99 23432 bytes
SHA-256: 348fa00a7ee4c58fb08dd0adfd79dd9e3c96c4c23b111568e8a0671f71f38d99