Malicious PDF — malware analysis report

Static analysis result for SHA-256 87231084de85cb87…

MALICIOUS

PDF

87.1 KB Created: 2021-06-26 22:34:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9c84e5b50483c41beb1cd5261c44fed1 SHA-1: 2f8987ae2073dff9c4b5331db7c18bcb37e2347d SHA-256: 87231084de85cb870c00c0e2ea0a1d7f5b8f20361f660f76fbb32774efe66d59
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to numerous compromised WordPress upload storage locations and disposable hosting sites. The embedded URLs, such as 'https://ketchas.ru/uplcv?utm_term=is+a+plant+cell+unicellular', are likely used to distribute further malicious content or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://ketchas.ru/uplcv?utm_term=is+a+plant+cell+unicellular
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/trbervu4hghls5to8mbttos9v7/90638582939.pdf
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/308f2d90e5722a0bb73b03bf9b5dd9ec/wipelasewi.pdf
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160904e4def5a6---mewapobitif.pdf
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/cedfd8abf304f74611f08d88f9368aa0/26785010416.pdf
    • http://kamkmori.cz/ckfinder/userfiles/files/23723263062.pdf
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/1824406513.pdf
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083655869798---13018421355.pdf
    • http://auxerretv.com/content/public/file/74604697263.pdf
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/89a27084069cd3a343589fbf127fca18/2024206422.pdf
    • http://wami.cc/data/files/zabetisawupivetuxu.pdf
    • http://fdscience.com/UPFILE/userfiles/files/33634150323.pdf
    • http://bettaletroom.com/file_media/file_image/file/1910493678.pdf
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c57865cc275---lejufotosinolugex.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac542caba99---pokapiduwatupewa.pdf
    • https://bellevuecommunityfoodbank.org/wp-content/plugins/super-forms/uploads/php/files/1fa02a9a2fa49c62e1b8cb06dfa164ab/venimujoregixigezubapini.pdf
    • http://alanaf.ru/userfiles/files/mufugumis.pdf
    • http://amctop.com/board_data/editor_img/file/202106081841.pdf
    • http://elmbbq.com/uploads/files/turarikaloxadunenulanal.pdf
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/ra2f2j1k9qc6dqihnggqcktcjo/rinefebelanupuper.pdf
    • http://residencecarlofelice.com/userfiles/files/nawinadakobolaren.pdf
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160775a234a787---73308123699.pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1608856278b6f7---wubudopomure.pdf
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/09debc1e6f56a9fa6291e2ecf2a2bec2/juxonokufilali.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a364586b128---58552218456.pdf
    • https://morethancleaningservices.com/wp-content/plugins/super-forms/uploads/php/files/9017e2d68dd996018f7d3d940733c428/zumokurugudadubitotuluba.pdf
    • http://dobrasekacka.cz/userfiles/file/bofafoxoginibaxoma.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f26f.bin
ae9b11265cdea37750315914081b732743bfe4934244b6d9113b20dd2df4c806
pdf-font-stream PDF embedded font (sfnt) at offset 0xF26F 17424 bytes
font_01_sfnt_off00011fa7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA7 16792 bytes
font_02_sfnt_off000137be.bin
5b5c522b696d3f2182b9c68ea88d6b45214c567ceb6e3657a3735cc51d84a03a
pdf-font-stream PDF embedded font (sfnt) at offset 0x137BE 10300 bytes