Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1103cf87bdb434c…

MALICIOUS

PDF

82.6 KB Created: 2021-09-01 10:22:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-18
MD5: f6d2e18aa8db2aa676e270e41343753b SHA-1: f04187fb8969646edcd54e5f3b5fb66aab2378a8 SHA-256: a1103cf87bdb434c9941ff9b07c4498cb35be0eca7e8a2c5069e7e718d14d658
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites. These links form a link farm, a common tactic for phishing or distributing further malware. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to a phishing campaign or a downloader.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16093ae8d8d466---64213904246.pdf In PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160aaee86be447---81480280225.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16096bc6c142e9---gibigijibogularep.pdfIn PDF document text
    • https://dom4m.by/userfiles/files/24266473278.pdfIn PDF document text
    • http://highspiritsmusic.com/ckfinder/userfiles/files/27877069635.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edd07578f78---70550678599.pdfIn PDF document text
    • http://musclecar-taps.com/js/upload/files/72936071129.pdfIn PDF document text
    • http://fantalife.nl/userfiles/file/rutagovapogemug.pdfIn PDF document text
    • http://ksnjl.com/userfiles/files/gobufaruzarere.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/160983d1cdc2d3---98932309089.pdfIn PDF document text
    • https://realestateconnect.us/wp-content/plugins/super-forms/uploads/php/files/v2ija0qrs83ug2q7n9025697s1/jisipozupoguri.pdfIn PDF document text
    • https://www.qlsny.com/wp-content/plugins/super-forms/uploads/php/files/f7cff54bb6b84ddcb3b1c1c85f965d1a/47216497130.pdfIn PDF document text
    • http://martonelektro.hu/files/file/21200706858.pdfIn PDF document text
    • http://hanasushi6.com/uploads/files/sipimixunidoravegelafu.pdfIn PDF document text
    • http://sedaciesupravy.sk/media/file/sovibiga.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c5cc29933e8---burewulep.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b8798b304f---pawesed.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/6mvbs1vaum0g1kccn3eg5ngpcp/padusigexawalunugi.pdfIn PDF document text
    • https://www.ideaklinikbursa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160707705a2318---67810353655.pdfIn PDF document text
    • https://foodsafebox.com/ckfinder/userfiles/files/27158418759.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/xiderafinuzivedebavesuxon.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608fcd4f7ed57---38905454873.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608299fce1312---wigaxekifi.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/rdmfv9iticu8s16b41li5rhclf/falesuberukinebuzu.pdfIn PDF document text
    • http://colantuono.it/userfiles/files/zetuwanemogarozenilul.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/xibokusofesenerafebezi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=west+end+musical+ticketsPDF 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_off0000e00e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE00E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f820.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF820 17032 bytes
SHA-256: 3f740e1c7c9730e7fd8df436e6de05c8196afd861472e6adddea2504d1d4a93f
font_02_sfnt_off0001244b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1244B 10496 bytes
SHA-256: 73bc936c2586b7985b369b009a968e07352aff5795c14850049e8bbc19d4bb5f