Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5ad886ed1f31cae…

MALICIOUS

PDF

69.8 KB Created: 2021-09-07 21:36:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 989df52d28bf466ce79b4fea6d156d9d SHA-1: 97f6d640e5302caa83c369a12b2e821fb370a6ad SHA-256: f5ad886ed1f31caeba3fc56d31861cc597f3c766d8257a6e7efee30732af4363
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a PDF link farm pointing to compromised WordPress uploads and disposable hosting, suggesting it's designed to redirect users to malicious sites. The embedded URLs, such as https://medvor.ru/uplcv?utm_term=reading+comprehension+passages+8th+grade+pdf, are likely part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://medvor.ru/uplcv?utm_term=reading+comprehension+passages+8th+grade+pdf PDF link annotation
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/d21ce2c807181b0fbaf617cd66c084a5/27626664173.pdfIn PDF document text
    • http://xlsferrosilicon.com/d/files/pegajabuvinudefipowan.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/73da1b67bc51f0257d04e6ae2cc5d0f7/59399706878.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/92571373374.pdfIn PDF document text
    • http://chayka-svg.ru/files/55892305450.pdfIn PDF document text
    • https://pass-eco-energies.com/ckfinder/userfiles/files/38455446637.pdfIn PDF document text
    • http://35ju.21tg.cn/uploadfile/ckeditor/files/xijomojukuxepazenakoso.pdfIn PDF document text
    • https://zzarosiscarampola.it/file/23508078541.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/82770373fbb0f6ebb2ffa6262688bf28/wijukizud.pdfIn PDF document text
    • http://lapenya.cat/imgjovesnaves/file/30175124087.pdfIn PDF document text
    • https://cincia.ro/ckfinder/userfiles/files/wakefagikimirozibo.pdfIn PDF document text
    • https://iasvn.org/Images_upload/files/6536163830.pdfIn PDF document text
    • http://kezheng.net/Upload/file/pilut.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/16076f6300dadf---48058448566.pdfIn PDF document text
    • http://bora.su/ckfinder/userfiles/files/jenidijim.pdfIn PDF document text
    • https://hung168.tw/UserFiles/files/56311636636.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c06a693370---xusoguxad.pdfIn PDF document text
    • http://openendrep.com/userfiles/files/13673555837.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/06e11d0u32j4f7mkt6q6p1rfn1/1653194545.pdfIn PDF document text
    • http://dmkert.hu/files/file/72462171176.pdfIn PDF document text
    • http://solarhomepage.ch/fckeditor/editor/images/file/zaregojekowexakipujekab.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/160bc2ad35ca91---15078200682.pdfIn PDF document text
    • http://alliance-ltd.com/userfiles/30815916850.pdfIn PDF document text
    • http://pytextiles.com/userfiles/file/sivuxul.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_off0000b272.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB272 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA89 11272 bytes
SHA-256: b0b4be0fda9106c7fe0051427a1127b0405efe7a69248f6ad51383a31f5d3c4e
font_02_sfnt_off0000e48c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE48C 14800 bytes
SHA-256: 9149f33090b6a5bb8629a2076bd917185bd9667808abd567f1a2f5365103ec25