Malicious PDF — malware analysis report

Static analysis result for SHA-256 6232c2091c27bf92…

MALICIOUS

PDF

76.5 KB Created: 2021-09-16 00:52:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c139cd44fd72d9c32e67cf1a19d33337 SHA-1: bd6b6a1e69c972bb48fadd6fe043680da3bd5222 SHA-256: 6232c2091c27bf92a666a55c871dd845bc93f7d66ef1f780bb18714b83de2724
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It functions as a link farm on disposable hosting, with numerous embedded URLs pointing to further PDF documents. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a deliberate attempt to obscure the true malicious nature by distributing links across many low-reputation domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=an+introduction+to+fluid+dynamics+batchelor+pdf PDF link annotation
    • http://rungrawin-itt.com/userfiles/files/24132946293.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/65307689831.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/161407f38c911f---pekelex.pdfIn PDF document text
    • https://www.notusweb.com.br/ckeditor/ckfinder/userfiles/files/dalagipupukoniwumumude.pdfIn PDF document text
    • http://orderleesushi.com/uploads/files/39077805668.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/89272516867.pdfIn PDF document text
    • https://sunnyvale.com/wysiwygfiles/file/vufadujolijowal.pdfIn PDF document text
    • http://cwpni.com/userData/ebizro_board/file/21488444842.pdfIn PDF document text
    • http://blackivy.pl/userfiles/file/mevomaragosofu.pdfIn PDF document text
    • https://pfollowers.com/ci/userfiles/files/82370721204.pdfIn PDF document text
    • https://novahealthclinic.ca/userfiles/file/34228994087.pdfIn PDF document text
    • http://elitsatodorova.com/uploadfiles/file/95646958787.pdfIn PDF document text
    • http://abbeloosschinkels.be/userfiles/file/68287245254.pdfIn PDF document text
    • http://queensparkview.com/image/upload/File/lisibufisa.pdfIn PDF document text
    • http://yuha.be/_files/file/tidavufoxim.pdfIn PDF document text
    • http://familiehollander.nl/images/uploadedimages/file/37626184794.pdfIn PDF document text
    • http://squash-fitness.cz/userfiles/file/migusobi.pdfIn PDF document text
    • https://glamweddingdesign.com/userfiles/file/49868253859.pdfIn PDF document text
    • https://creteotels.gr/FCKeditor/userimages/file/monala.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/0268a85d554fde0fb77dede331bf0145/26890219316.pdfIn PDF document text
    • https://www.igescanada.com/ckfinder/userfiles/files/93645818946.pdfIn PDF document text
    • https://bushregenerators.com/userfiles/files/597631372.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/webijotulebejas.pdfIn PDF document text
    • http://mg001.cn/upload_fck/file/2021-9-12/20210912122851815674.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/tutoritusa.pdfIn PDF document text
    • http://excitechem.com/userfiles/file/13937502985.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_off0000c56d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC56D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD7F 16980 bytes
SHA-256: 5ab68339fcea90667c888af3664f066ab534e1cb030fbd7be4858ec479832223
font_02_sfnt_off000109e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109E5 11220 bytes
SHA-256: 3cde808ffec0d8c56db753cc6ce0ca330dab08158a18463b1d0dec5a26bda3b0