Malicious PDF — malware analysis report

Static analysis result for SHA-256 80cb1599211bcb8b…

MALICIOUS

PDF

75.4 KB Created: 2021-09-24 13:54:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ffc1ca57d44042389c25f74371899fdf SHA-1: 27aa5c3dca150d3da0202e517ac19981feca36e8 SHA-256: 80cb1599211bcb8b686ad2583779a41b56c478cdc064a9fbb9e6d365dc4ab130
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The presence of numerous external URIs and a link farm structure suggests an attempt to redirect users to malicious content. The document body, though heavily obfuscated, contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create PDF documents from web content, further supporting the link farm hypothesis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://ketchas.ru/uplcv?utm_term=time+freeze+apk PDF link annotation
    • http://hataylezzeti.com/resimler/files/96046328234.pdfIn PDF document text
    • http://toyotarent.kr/FileData/ckfinder/files/20210903_1BC60852647A5DA7.pdfIn PDF document text
    • http://hamzalegalservices.com/userfiles/file/supipelewolamudoxaxotilup.pdfIn PDF document text
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/84554271888.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614c57b19c6f7---moginajepi.pdfIn PDF document text
    • http://luxmeterthai.com/ckfinder/userfiles/files/65411234299.pdfIn PDF document text
    • http://materialdeestudo.top/userfiles/files/83281970594.pdfIn PDF document text
    • https://ltes2.tw-goods.com/UserFiles/files/64047669556.pdfIn PDF document text
    • https://taipeitccia.org/CKEdit/upload/files/39920233425.pdfIn PDF document text
    • http://baovekhucongnghiep.com/upload/files/kisafazen.pdfIn PDF document text
    • http://xn--80aa5alfu.kz/file/42583788172.pdfIn PDF document text
    • http://duetsepolno.pl/userfiles/file/33925186418.pdfIn PDF document text
    • https://thefertilizergranulator.com/d/files/13962456714.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614c14c5eca76---meruwama.pdfIn PDF document text
    • https://msiutilities.net/documents/31510707765.pdfIn PDF document text
    • http://robertoantoniz.com/resources/original/file/nemoguwazu.pdfIn PDF document text
    • http://ferrocom-spb.ru/userfiles/files/66935415682.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/jolipexesex.pdfIn PDF document text
    • http://kwartetproforma.com/userfiles/file/56855517555.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614cb06816180---jerabevaxa.pdfIn PDF document text
    • http://firesecurity.sk/userfiles/file/zotafaso.pdfIn PDF document text
    • http://inbond-cn.com/userfiles/file/tozitamolun.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/e78e87cd51c8bb595681531517216724/16047934171.pdfIn PDF document text
    • https://thic.muki001.com/plugin/ce1/ckfinder/userfiles/files/21053141675.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_off0000c25f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC25F 18064 bytes
SHA-256: 179dc92fb6c7f75d0136583a81b0c5f1375657139a7581edc7a7e4cfdfd2c266
font_01_sfnt_off0000f179.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF179 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010990.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10990 10100 bytes
SHA-256: 1845a115cf03c7f1a1b77361c857339918de7d810726c7ebd7dc0d654d02d278