Malicious PDF — malware analysis report

Static analysis result for SHA-256 a73f6f723e041211…

MALICIOUS

PDF

69.0 KB Created: 2021-09-25 01:25:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ec316ae95c2c36fa1c66ebb3443e0986 SHA-1: cd8bb680ca67b9add280e7c4d8ee83d41e08b9ec SHA-256: a73f6f723e04121114b0bb04d7190221a5bfa2b2733b9df8cc57ac5d7eda2815
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Numerous heuristics indicate the PDF is a link farm, with many external URIs pointing to compromised websites or disposable domains. The document body is unreadable, but the presence of multiple external links suggests an attempt to redirect the user to malicious sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://pistant.ru/uplcv?utm_term=winzip+for+android PDF link annotation
    • https://schachverein-marchhoefe.ch/fcsr/news/upload/file/tadevumew.pdfIn PDF document text
    • http://musicincw.com/fckeditor/userfiles/image/timufabuji.pdfIn PDF document text
    • http://oreade-breche.fr/userfiles/file/lugoxugenod.pdfIn PDF document text
    • http://www.shjkyq.com/up_files/FCK/file/dumozagujoruteve.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/ebb095f0740e02268ad5d475dcbd1ff8/40460130873.pdfIn PDF document text
    • http://locnuocvietmy.com/Images_upload/files/wixen.pdfIn PDF document text
    • http://smogy.ru/files/files/danozopoti.pdfIn PDF document text
    • http://restavratorstvo.com/ckfinder/userfiles/files/noziwigukobutifelogoko.pdfIn PDF document text
    • https://bodykneadstherapy.com.au/ckfinder/userfiles/files/kovej.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/7447867cf1abf08b7bc5b99ed0ae2f9c/nopidaledusu.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/2555c8864040ac75d86a0dc615e33d28/37071380545.pdfIn PDF document text
    • http://burbank.kopanramen.com/uploads/files/58106448660.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/0111aad70dd088d82497da098f257f81/repidadowiseludaxuz.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/06jr9f866ec19qtlrru16fk83m/deserovakijitekava.pdfIn PDF document text
    • http://www.jasfec.com/imgs/uploads/lijizaregozumepeno.pdfIn PDF document text
    • http://coomargroup.com/ckfinder/userfiles/files/26313734002.pdfIn PDF document text
    • https://vwb.mrv-educationservices.com/content_file/files/dumusupiputolosowuxapodos.pdfIn PDF document text
    • http://csc-021.com/userfiles/file/20210911011208_hbb6ka.pdfIn PDF document text
    • https://petribax.nl/userfiles/file/74651786107.pdfIn PDF document text
    • http://studioschicchi.eu/userfiles/files/33270832761.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef183efabf---41822116066.pdfIn PDF document text
    • http://eakqshop.com/ckfinder/images_store/files/42311505357.pdfIn PDF document text
    • https://healthresearchinstitute.net/userfiles/file/zegomogigumekope.pdfIn PDF document text
    • http://zeshengtecphar.com/UploadFiles/FCKeditor/20210906105456.pdfIn PDF document text
    • https://coevent.ru/upload/files/zegovupaxukime.pdfIn PDF document text
    • http://ersenergy.com/UserFiles/file/99410659543.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_off0000b1d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1D0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9E7 10100 bytes
SHA-256: 036cfc72b919bf0484f43239eccbe6190f2c9c097a6b4144bc1b8bc021ca9dbb
font_02_sfnt_off0000e079.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE079 15196 bytes
SHA-256: ef522d53415454c4f88b7ae50080ad8dc3bafce01dee9c219cb547e4a877ec22