Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8af7b287e5497a7…

MALICIOUS

PDF

83.5 KB Created: 2021-09-19 07:04:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b2a8acf413236d0491b011a5299d64c4 SHA-1: 405321721dd9ada71302f8d0670b4610e4505ccd SHA-256: c8af7b287e5497a7899f4c81e70b7e5605afc9eaa24e0e54a0e730b689d97411
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm hosted on disposable domains. The primary function appears to be redirecting users through a series of links, likely to a phishing page or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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 http://dulichtantai.com/files/uploaded/files/6425541160.pdf In PDF document text
    • https://forumhrdbekasi.com/webroot/userfiles/files/99231249223.pdfIn PDF document text
    • http://internationalnetworksolutions.net/files/In PDF document text
    • https://yasacompany.com/upload/files/votilumugevavamezupu.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613d018870f1f---67871888019.pdfIn PDF document text
    • https://dd-inside.de/userfile/file/41591521296.pdfIn PDF document text
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/67878188241.pdfIn PDF document text
    • https://maychieuvinh.vn/upload/files/fidegamejepujanezajud.pdfIn PDF document text
    • https://kocarbon.vn/luutru/files/44622238876.pdfIn PDF document text
    • http://www.bongbansaigon.com/uploads/files/sobadilojixuxujip.pdfIn PDF document text
    • https://madeirashopping.com/userfiles/file/55024543750.pdfIn PDF document text
    • http://mannadey.in/FCKeditor/file/vazopofoposibewes.pdfIn PDF document text
    • http://michardardillier.com/ckfinder/userfiles/files/zaxesozosa.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/d012de3e55be7185a9a73836b76a8f76/xukufufomusasobonifexa.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161391d6b3bac5---55750637982.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1631721110.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161448dc64401f---18185547118.pdfIn PDF document text
    • http://efuegypt.org/userfiles/file/65680807594.pdfIn PDF document text
    • https://robert-zauer.cz/userfiles/file/11604959308.pdfIn PDF document text
    • http://foxadv.net/file/49874113307.pdfIn PDF document text
    • http://beiwendq.com/userfiles/file/defesixupabubenixori.pdfIn PDF document text
    • http://market-oborudovanie.ru/upload/file/5330511337.pdfIn PDF document text
    • http://yeditepegumruk.com/userfiles/45355382271.pdfIn PDF document text
    • http://newgrids.com/userfiles/file/wagufejib.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/509b76703255427ed6c8f41a437b2127/1277980116.pdfIn PDF document text
    • https://fleseriuassociates.ro/files/file/91092834243.pdfIn PDF document text
    • https://vocembalo.ch/userfiles/file/63841440925.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=catch+notes+app+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_off0000e3e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E4 10596 bytes
SHA-256: 641cccad0bc07f1c20f5974034b5d144f07f8ac1a03c6aae1516c487f18fad52
font_01_sfnt_off0000fc0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0F 17084 bytes
SHA-256: 299417171b247f6aca3b7984f57f316d607f46ad1ba33c57cf37e51b1e565ded
font_02_sfnt_off0001283e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1283E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1