Malicious PDF — malware analysis report

Static analysis result for SHA-256 756f165226d0ab0e…

MALICIOUS

PDF

71.8 KB Created: 2021-09-28 15:27:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 240cb4f38c380f9894024fa109ad826b SHA-1: 599f0e5a0b88bbbb9e87c9b0d4fe4923cc1a1582 SHA-256: 756f165226d0ab0e667cff942d314e7d83c2b1721ccb5b8ef1a866f708d4dc39
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous external URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The PDF structure itself is also noted as having duplicate object bodies, a common obfuscation technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://infrive.ru/uplcv?utm_term=motores+neumaticos+pdf PDF link annotation
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614211303053b---xijebotozalemafukiz.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/7f1a442ae983f541b53835543c842a17/30613599132.pdfIn PDF document text
    • http://diskacme.dk/images/upload/file/69004094208.pdfIn PDF document text
    • https://reha.bg/content/upload/file/80961280593.pdfIn PDF document text
    • http://automozg.by/upload/editor/files/30696986918.pdfIn PDF document text
    • http://bulk-supplies.com/userfiles/files/11957480173.pdfIn PDF document text
    • http://teedinmaesai.com/user_img/file/9692002823.pdfIn PDF document text
    • https://gilbertems.com/videos/file/26315118483.pdfIn PDF document text
    • http://www.ferm-matic.fr/upload/file/34054154667.pdfIn PDF document text
    • http://myphamlulanjina.com/upload/files/woxop.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/tanadatin.pdfIn PDF document text
    • http://1855-4080.com/userfiles/file/18590237312.pdfIn PDF document text
    • http://namngonviet.com/user-/files/xepitibew.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613f56c01d85d---fapemogedibelazip.pdfIn PDF document text
    • http://ozdesignhouse.com/app/webroot/uploads/files/jerijoritowokonidunisune.pdfIn PDF document text
    • http://webbuilders.com/files/file/93172011455.pdfIn PDF document text
    • https://pyccenter.com/images/Upload/file/gozisaxebexow.pdfIn PDF document text
    • http://jadever.vn/Images_upload/files/69528225495.pdfIn PDF document text
    • https://www.assofmt.org/ckfinder/userfiles/files/wuzuxuduvopuv.pdfIn PDF document text
    • http://mrspk.com/ckfinder/userfiles/files/xiserumevuzejimodaximo.pdfIn PDF document text
    • http://yavuzselimvakfi.org/resimler/site/files/bamexowigifira.pdfIn PDF document text
    • http://ttlh.vn/storage/ckfinder/files/63346377456.pdfIn PDF document text
    • http://xsjsbzrw.com/uploads/files/vasapubipakaminofomene.pdfIn PDF document text
    • http://zkmeiqi.com/admin/ckfinder/upfile/files/pojinolajomukenoluxazude.pdfIn PDF document text
    • https://indicaperu.com/userfiles/file/bewemamufanigebived.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_off0000b691.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB691 16548 bytes
SHA-256: dc0f755547f8f2798acb60557e7b1b37e58c27a3b6c7d99c645060d9da278e33
font_01_sfnt_off0000e109.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE109 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f920.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF920 10828 bytes
SHA-256: 36d252581d6726a8e9f6f4cf73e790df936c6afccb848f809bd36fb9b1872125