Malicious PDF — malware analysis report

Static analysis result for SHA-256 605cead28cdc564d…

MALICIOUS

PDF

81.5 KB Created: 2021-09-13 23:04:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 848ad23ad0aeca595f14d3c70922b5f2 SHA-1: 1a62c39a63dc2d1cdf7da18f8ff57dce600c9dbc SHA-256: 605cead28cdc564d720e4e22d19de98abaa86070013e9e926f51c9e6349fd60b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. The presence of numerous external URIs and link farm heuristics points towards an attempt to manipulate search engine results or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://cosmikkino.ru/sadm_files/relagumujeke.pdf In PDF document text
    • http://gokea.org/upload/editor/files/77624706602.pdfIn PDF document text
    • http://tourhong.com/FileData/ckfinder/files/20210905_94C88C88656BB086.pdfIn PDF document text
    • https://sanaspinler.net/calisma2/files/uploads/zasefaluk.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/16139d2e072735---kagozibedozot.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/gixejumusujaz.pdfIn PDF document text
    • http://tetobox-budapest.hu/uploads/files/zedatorumorivowebaz.pdfIn PDF document text
    • https://krassimirtaskov.com/userfiles/files/8095330916.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bd28e8cd4e---golumuri.pdfIn PDF document text
    • http://joltiy.ru/uploads/files/49772178950.pdfIn PDF document text
    • https://frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/7930916569.pdfIn PDF document text
    • http://taxplus.in/images/contentimages/files/worokinatisapigurov.pdfIn PDF document text
    • https://sevenhillsgroup.net/ckfinder/userfiles/files/61310816198.pdfIn PDF document text
    • http://occahomesearch.com/userfiles/files/dowev.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16136789ae7223---17648817428.pdfIn PDF document text
    • https://kovtec.pl/eurostyl/photos/file/7877488366.pdfIn PDF document text
    • https://cubic.is/userfiles/file/64289423064.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/masazagovobiwelaxi.pdfIn PDF document text
    • https://envida-nieuws.nl/bsb_website/upload_fck/file/zasoruxevowuta.pdfIn PDF document text
    • http://santabruna.cl/upload/file/jolukamepev.pdfIn PDF document text
    • https://egca.fr/userfiles/file/samezoserosag.pdfIn PDF document text
    • http://rtm-plus.ru/ckfinder/userfiles/files/48590160659.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=best+5+phone+under+15000+in+bdPDF 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_off0000d6ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6AE 10884 bytes
SHA-256: 7bf0062657b3cfc566498634f3f9b67d48f3157511788b075dfbe9916a45c2f5
font_01_sfnt_off0000ef9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF9F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107B1 18940 bytes
SHA-256: 9a72dc0efd2a6b743574f4e0398d1910bc093c95386f007fbb99ceac85686efc