Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1da0d0873d71058…

MALICIOUS

PDF

76.5 KB Created: 2021-09-21 19:56:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6ced8eb9061405df2be2b894260ada6e SHA-1: a1706dcf6f1613f8073d028a94670f2827e2f344 SHA-256: d1da0d0873d71058e3e70dc0b6f510232d36816dbcf730c087c7ddf90111e0ab
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous external URLs, many pointing to disposable domains and acting as a link farm, strongly suggests a phishing or malware distribution campaign. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL usage are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://synerhu.ru/uplcv?utm_term=biological+psychology+by+james+kalat+13th+edition PDF link annotation
    • http://galeriejacqueselbaz.com/userfiles/file/39328226575.pdfIn PDF document text
    • https://mobilpetrol.olajpark.hu/files/files/68197107523.pdfIn PDF document text
    • https://ripedzn.com/app/webroot/files/fckeditor/file/dekifirotubokamev.pdfIn PDF document text
    • http://husplaza.hu/editor_up/buwajepejafa.pdfIn PDF document text
    • https://skvacations.com/userfiles/file/nofogopevitosobaduno.pdfIn PDF document text
    • https://chungangroup.com/uploads/files/202109011252047662.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/90794014539.pdfIn PDF document text
    • https://eastoncn.housemember.com/uploads/files/kisalijikozipoxijoxo.pdfIn PDF document text
    • http://automozg.by/upload/editor/files/mutefapoma.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/bk4ppa12lcb624u8iva5rum4ki/18871793587.pdfIn PDF document text
    • https://bibonatura.com/ckfinder/userfiles/files/somenafupilevagolojova.pdfIn PDF document text
    • https://siahotel.com/userfiles/files/66855636777.pdfIn PDF document text
    • https://rt-totaalafbouw.nl/userfiles/file/worobadirevud.pdfIn PDF document text
    • https://ezokniga.com/uploads/file/relobebujezuxuvipikam.pdfIn PDF document text
    • https://holycrosshealthcare.com/userfiles/files/65482743096.pdfIn PDF document text
    • https://i-intelli.com/ckfinder/userfiles/files/76784100746.pdfIn PDF document text
    • http://df-2.de/images/daten/file/18038369062.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/55540100813.pdfIn PDF document text
    • http://2478.ru/admin/ckfinder/userfiles/files/49897667861.pdfIn PDF document text
    • http://rilta.net/userfiles/files/zuvumawuwamibiwubemet.pdfIn PDF document text
    • http://hicoweld.com/shop/fck_file/file/sokuralevuxigutoko.pdfIn PDF document text
    • http://huarui-bio.com/upload/files/bukogubewikawed.pdfIn PDF document text
    • http://kaus21.com/userData/board/file/27786911636.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/xopajukek.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_off0000c432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC432 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC44 17044 bytes
SHA-256: 3e145cd4f03485120923420e7e908092bd3a3e7f8a31636c7db4c81b25089656
font_02_sfnt_off0001088d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1088D 11612 bytes
SHA-256: 677720f67f2ba19e0fb7f0b568c066daa39185897ac0dae0515ba34c43472f6d