Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c37a6e4abfd93a6…

MALICIOUS

PDF

84.3 KB Created: 2021-09-17 14:08:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f3e3edddb6af0e4c946bd69ce9c0db1f SHA-1: 5641296bd29e662cac2a090883e94c8cbf4913cd SHA-256: 7c37a6e4abfd93a6b31948bf0d2185a725554efd7b491edc4fddbeef9f7bd231
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous external URIs and a link farm structure suggests a phishing or SEO poisoning attempt. The document body is heavily obfuscated and contains no readable text, preventing a more detailed analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://catamma.ru/uplcv?utm_term=repair+corrupted+jpeg+files+android PDF link annotation
    • http://contactfm.be/userfiles/files/fuwotoxesudir.pdfIn PDF document text
    • http://feuerwehrobrigheim.de/upload/files/84596888493.pdfIn PDF document text
    • http://restavratorstvo.com/ckfinder/userfiles/files/rojubexapozenisufaxok.pdfIn PDF document text
    • http://filtrydokoparek.pl/img/all/33891739405.pdfIn PDF document text
    • http://radio-salsa.com/php/rs/filesupload/file/magasivep.pdfIn PDF document text
    • https://ijaetis.org/ckfinder/userfiles/files/jowufoxuvefivosatavep.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/wagafo.pdfIn PDF document text
    • https://magerp.org/upload/files/dekikonudopeve.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/kalofutafesalago.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/bifame.pdfIn PDF document text
    • https://alshuka.ps/ckfinder/userfiles/files/77081671929.pdfIn PDF document text
    • http://commissioncollectionlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tipetowowavo.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/09/files/210911061108.pdfIn PDF document text
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/vugenagafer.pdfIn PDF document text
    • http://olymp-kiev.com/temp/fckeditor/file/dobujomexabifimob.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/41793236488.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/04cdd30a673af1a60214029663be1d8e/mijujudogijamet.pdfIn PDF document text
    • http://nriloan.jctoursandtravels.in/files/lexabo.pdfIn PDF document text
    • http://hoteldazegliotorino.com/userfiles/files/migafedezulezibetiw.pdfIn PDF document text
    • https://hotlinepro.in/admin/userfiles/file/sabovutadup.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/mezojemeva.pdfIn PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/73070010307.pdfIn PDF document text
    • https://y3stwk65l-mn9.com/contents/files/sapagupuwaluli.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138ed5106776---9785777010.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_off0000de8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE8D 11068 bytes
SHA-256: fb3516572bf76c0842b23c0c636bd83fdc583c5b3290bf50d92986635dc03383
font_01_sfnt_off0000f838.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF838 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001104a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1104A 19760 bytes
SHA-256: 9a38e963388ca71c41cf0118e3ef510c66cb2b72c16ce1990a004011c0692bfa