Malicious PDF — malware analysis report

Static analysis result for SHA-256 37a248022ebd5f56…

MALICIOUS

PDF

79.0 KB Created: 2021-09-11 18:59:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 947e511d25e95a9a081138be7dad7e3b SHA-1: 76498168add05d09b76db07d899fb134bf51e0ee SHA-256: 37a248022ebd5f56a7024735fd5dbb3f5aef987ed926bcb81d628abb4992b6e9
126 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, with numerous distinct hosts and links pointing to PDF files, likely to obscure the final destination. The embedded URLs, such as http://expertsystemgroup.com/file_media/file_image/file/detixomasagivigakusud.pdf, are likely part of this redirection chain, aiming to deliver a phishing page or a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://expertsystemgroup.com/file_media/file_image/file/detixomasagivigakusud.pdf In PDF document text
    • http://graczeonline.pl/userfiles/file/buvezakoro.pdfIn PDF document text
    • https://razdolle.by/wp-content/plugins/super-forms/uploads/php/files/213qqfhgmnhul01asqc7ool730/10949545378.pdfIn PDF document text
    • http://studioprogettoarchitettura.eu/userfiles/files/wunafoguvazewopobezadage.pdfIn PDF document text
    • http://alphanaturehk.com/userfiles/file/xipodolaxakojukox.pdfIn PDF document text
    • http://kaztelcom.kz/ckfinder/userfiles/files/gugejedimivelalujogonew.pdfIn PDF document text
    • http://chip-chup.hu/upload/file/65271498359.pdfIn PDF document text
    • http://f-kcc.jp/user_data/userfiles/files/vezotiwameki.pdfIn PDF document text
    • https://chambres-hotes-aube-bleue.fr/userfiles/file/girakosinemekolo.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/negovamivogojukejelejap.pdfIn PDF document text
    • https://tsegypt.com/file/44166550834.pdfIn PDF document text
    • https://cortemadera.com/wysiwygfiles/file/56230858963.pdfIn PDF document text
    • http://urotunisia.com/uploads/FCK_files/file/59558625798.pdfIn PDF document text
    • http://tpt.taipei/asset/uploads/files/nuwilovukejisowajaresoben.pdfIn PDF document text
    • http://candientuvibra.com/images/file/32657075865.pdfIn PDF document text
    • https://hsiaoying.com/userfiles/file/bujavinapujan.pdfIn PDF document text
    • http://ipcmanpower.com/admin/style/images/userfiles/file/mexagupigamodobe.pdfIn PDF document text
    • http://vinaktv.com/storage/ckfinder/files/50814885998.pdfIn PDF document text
    • https://rowadalbyt.com/userfiles/files/pofanataxe.pdfIn PDF document text
    • https://gabinetpro.pl/kosmetyczka/krakow/files/fosorage.pdfIn PDF document text
    • http://sms-dk.com/FileData/ckfinder/files/20210907_6A668E32606202AE.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/1613be6b608bf3---67398454976.pdfIn PDF document text
    • http://mizuho-co.net/file/ck/files/ribavewenovixizeruz.pdfIn PDF document text
    • http://deshdunya.com/blogimage/file/pitoribu.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/e6ace419b0c8c94a1963300586cac304/92483375530.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=add+caption+to+photo+androidPDF 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_off0000d366.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD366 10244 bytes
SHA-256: 31702a5e8db8388141ebf3ef0d30c6d6e07812fa79e1358fbf386f7c733b9c2c
font_01_sfnt_off0000ea4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA4E 16928 bytes
SHA-256: cba4253d25ce5ce7fcd2f8f07344eca2c6d946840ce7f8c240f18ba3b6492f49
font_02_sfnt_off0001164f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1164F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1