Malicious PDF — malware analysis report

Static analysis result for SHA-256 7dc8c9c9beb788dd…

MALICIOUS

PDF

84.7 KB Created: 2021-09-07 03:05:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9c63087d5c400a14542ebe9be7a791d2 SHA-1: 851110eed69ee45fdbe0494bf89e9fd6220a34a2 SHA-256: 7dc8c9c9beb788dd84e0caee5e7b319936dfa0b1d9ab6f2d141acf1ac8aa5bc4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress upload storage and other domains, suggesting it's part of a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, indicating an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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 http://agataklimowska.pl/userfiles/file/katufobuladudedev.pdf In PDF document text
    • https://fototipia.hu/files/files/8708057153.pdfIn PDF document text
    • http://runbo.net/upfiles/files/16309634013031.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb4cb534de---wivamusuvudekexujoton.pdfIn PDF document text
    • http://1-cities.com/blog_images/blog_/file/52104679045.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/fb49lidpr693750ne4g4bk0bs7/puganodukexisikipo.pdfIn PDF document text
    • http://j-line.ca/fck_upload/file/kiredo.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/53e3d619453c9d791db110f364da1570/moranojukubetopo.pdfIn PDF document text
    • http://mikailang.net/userfiles/file/20210811062015_1485609363.pdfIn PDF document text
    • https://www.nickelmarket.co.za/includes/ckfinder/userfiles/files/mipamolo.pdfIn PDF document text
    • http://kunjipsc.com/uploads/files/4005843518.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f21440c50b---bosubariwajabikalop.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/kisonezusipevosa.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bb55772f551---futonabixas.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160cf40c877e4c---14845996382.pdfIn PDF document text
    • https://dienlanhhonganh.com/images/pic/file/watumamadorekufuz.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160897fe2a6edb---14362414442.pdfIn PDF document text
    • http://abwjefferson.com/uploads/files/tefokuvefeni.pdfIn PDF document text
    • https://alice-immo.com/userfiles/file/kolagagatur.pdfIn PDF document text
    • https://ka-base.no/images_content/file/bibinonexidanulalonufag.pdfIn PDF document text
    • http://konsultacjenaukowe.eu/Upload/file/25518128002.pdfIn PDF document text
    • https://pinyardim.com/calisma2/files/uploads/61675171169.pdfIn PDF document text
    • https://centrorevisionimonregalese.it/file/puropadubobivasakemolixin.pdfIn PDF document text
    • http://thaisomboonautopart.com/userfiles/files/91209688840.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/67e186227c157739b71a346817458957/48684100271.pdfIn PDF document text
    • http://mizuho-co.net/file/ck/files/fetejutagewupobe.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16076e3481a2dd---43102066371.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=clenergy+mounting+pdfPDF 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_off0000e445.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE445 10756 bytes
SHA-256: 98687889d8b2817c8e9237ba9ccb67cdf6a40e12f28e4c45471a2167125a3300
font_01_sfnt_off0000fcc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCC9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000114db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114DB 18608 bytes
SHA-256: 48da0ac7da54cd177a1a1dcc7c175405c0772e5b1d0dfe3aa2368af026767fb4