Malicious PDF — malware analysis report

Static analysis result for SHA-256 85d1ae28542b7766…

MALICIOUS

PDF

79.0 KB Created: 2021-09-26 21:02:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 9505e22efd60c9bdb9d88e801bc8a941 SHA-1: 943194924f625e02780c0da97259d368fc9b6506 SHA-256: 85d1ae28542b7766ac50cd4b46a1e44d0e3f8dbe8d719f85b86b7b5dd4cf7977
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. The file's structure and URL patterns are consistent with a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://coretry.ru/uplcv?utm_term=how+to+install+base+apk+on+android PDF link annotation
    • https://asiahealth.standrewsdentalsurgeons.com/ckfinder/userfiles/files/29824561846.pdfIn PDF document text
    • http://ominocoibaffi.it/userfiles/files/77514689312.pdfIn PDF document text
    • http://werder-ritter.de/UserFiles/File/jobobesesebimamonine.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/71342000839.pdfIn PDF document text
    • http://marinapogon.pl/upload/file/36078753261.pdfIn PDF document text
    • http://almawred-sy.com/files/adminfiles/files/beweba.pdfIn PDF document text
    • https://buonoantonio.it/userfiles/file/97597778688.pdfIn PDF document text
    • http://timebymtm.com/upload/files/13630260387.pdfIn PDF document text
    • https://arrayamed.com/userfiles/file/xugebesume.pdfIn PDF document text
    • http://kommunikator.nu/demo/userfiles/file///lomozabidilomovitomexup.pdfIn PDF document text
    • http://trubaopt.ru/content/file/79044037279.pdfIn PDF document text
    • https://worldpigment.com/image/upload/File/zonare.pdfIn PDF document text
    • http://gmkms.net/upfile_editor/2021/files/45744657650.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613956d343936---junigiruwetawuvufuwawe.pdfIn PDF document text
    • http://sushiyaslo.com/uploads/files/14225983710.pdfIn PDF document text
    • https://papiratisk.cz/soubory/84449661990.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/t7najpdju0dg5ffdamkmc2rjcq/38043198138.pdfIn PDF document text
    • http://studiotecnicomartani.eu/userfiles/files/xoxisuzemutapepeturovif.pdfIn PDF document text
    • http://findmecakes.com/userfiles/files/tatazijizexiragifula.pdfIn PDF document text
    • http://ityab.com/cache/fck_files/file/jigubow.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/86572679787.pdfIn PDF document text
    • http://studioesflores.pl/obrazy/file/34006069086.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16136710d6e118---16534105454.pdfIn PDF document text
    • http://turnyras.lt/Files/file/ropiwojirogetogorul.pdfIn PDF document text
    • https://transmilenio.net/datamont/userfiles/file/15244666139.pdfIn PDF document text
    • http://tarasovfabrika.ru/uploads/file/85659129765.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_off0000c9ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e1ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FF 19592 bytes
SHA-256: 2d9cdab7d9cbf13ad120893c4a35f1fc62e542c688671444d9107f677773f1bc
font_02_sfnt_off000115b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115B4 10692 bytes
SHA-256: dc1f61eda7ba9753450e4ee22b19cb040ac2a52bd0f81c77a1f87514f8328399