Malicious PDF — malware analysis report

Static analysis result for SHA-256 c107218646e8f5c4…

MALICIOUS

PDF

79.6 KB Created: 2021-09-13 13:21:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 32392bb6b0f9e4df0d568f6ff17b1bab SHA-1: f555e88e6601f17ba9f1748658e58d22d4937d51 SHA-256: c107218646e8f5c4d22059caecb2a4fe68572c174ecfd5cbf08e24c170a80ec7
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous external URIs pointing to other PDF files hosted on distinct, potentially disposable domains. This suggests a multi-stage attack where the initial PDF serves to lure the user into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://coretry.ru/uplcv?utm_term=apps+to+flash+android+phone PDF link annotation
    • http://analhospital.net/file/files/sedenojujalafixigemako.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/698bb2c9a948502b5671a61c442463a6/ginawajaberov.pdfIn PDF document text
    • http://kaithompson.com/userfiles/file/25044887966.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/gosokuxuvenosiwugelidaza.pdfIn PDF document text
    • http://uchid.com/uploads/file/26656003590.pdfIn PDF document text
    • http://phoiinnhiet.com/images/uploads/files/malezigikomevomo.pdfIn PDF document text
    • http://samurairamenbar.com/uploads/files/peturumijebubuwisewadufi.pdfIn PDF document text
    • http://sovaimm.it/userfiles/files/ximitixumera.pdfIn PDF document text
    • https://mandarinusa.com/userfiles/file/1631094657.pdfIn PDF document text
    • https://medius.sk/userfiles/file/gamiwej.pdfIn PDF document text
    • http://hockeydh.com/files/ups/files/pikukozozar.pdfIn PDF document text
    • http://ambulatorioveterinariocigliano.com/userfiles/files/nabovuzuzub.pdfIn PDF document text
    • https://em.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/zirixe.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138e2fccd85e---zoxenobudofexejevora.pdfIn PDF document text
    • http://cannamelis.com/userfiles/file/tamazulifeloniruwaz.pdfIn PDF document text
    • http://sun-green.eu/ckfinder/userfiles/files/notusepilojele.pdfIn PDF document text
    • http://praguynakorn.com/praguynakorn/picture/datapro/files/38120302329.pdfIn PDF document text
    • http://dedanskecasinoer.dk/userfiles/file/rojekuvibubokibuto.pdfIn PDF document text
    • http://intelekt.biz/uploads/pages/files/74796418434.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/utida.pdfIn PDF document text
    • http://bscsaoner.in/ckfinder/userfiles/files/183882179.pdfIn PDF document text
    • http://riph.pl/userfiles/file/7317288521.pdfIn PDF document text
    • http://akvari-um.ru/userfiles/file/sofamovoletukajogob.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_off0000d24b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD24B 10576 bytes
SHA-256: c7eb515ba6bbe36229c5a98483e769d45d89178e0ea160a3820e0ae19acdf73c
font_01_sfnt_off0000ea62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA62 17996 bytes
SHA-256: 04d8e75dbdb7e3a38c80ad48105ba8d159a196af69a512ac23c6bd4e8db53fcc
font_02_sfnt_off00011951.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11951 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1