Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b7d28c43a8a9095…

MALICIOUS

PDF

79.4 KB Created: 2021-09-11 06:25:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1ef3bd5054f2641ceb3bbb6744ba8723 SHA-1: 3b265aa53c4c44a2d99d6e71289e5399fce7d4ce SHA-256: 1b7d28c43a8a90950ee8ea23ca9d01abb692070f965e9ee0a443b5d1f44d59b3
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which are algorithmically generated and hosted on disposable domains, indicating a link farm or phishing lure. The ClamAV detection and ML classifier strongly suggest malicious intent. The presence of external URIs and a link to a potentially malicious URL points towards a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://laborke.ru/uplcv?utm_term=android+remove+screen+lock+disabled+by+administrator PDF link annotation
    • http://kkslavicin.cz/sites/default/files/file/92543608652.pdfIn PDF document text
    • https://dichvuhappyhouse.com/upload/files/ruviz.pdfIn PDF document text
    • http://htbestcomputer.com/media/ftp/file/vamifajuxena.pdfIn PDF document text
    • http://hotelalbicia.com/userfiles/file/67072021833.pdfIn PDF document text
    • http://djpress.pl/Image/files/ropamezojujalewifuv.pdfIn PDF document text
    • https://przyklejki.pl/userfiles/42147881239.pdfIn PDF document text
    • http://droneducational.com/admin/userfiles/file/sanesewutoforopugedimomo.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/1506950890.pdfIn PDF document text
    • http://www.terresdescaraibes.fr/file/11858920818.pdfIn PDF document text
    • https://agronlogistics.com/userfiles/files/65460614458.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/e3d2fc90e3cad25f42b09305c109f7f1/97472421035.pdfIn PDF document text
    • http://cosmik-kinoteatr.ru/sadm_files/genibabemu.pdfIn PDF document text
    • http://stonepigments.com/userfiles/file/lesobovuborivu.pdfIn PDF document text
    • https://facades-et-traditions.com/actualites/file/41534973815.pdfIn PDF document text
    • http://christmaslandint.com/userfiles/duvutuvupefuwon.pdfIn PDF document text
    • https://orsam.org.tr/paketler/ckfinder/dosyalar/files/13407033400.pdfIn PDF document text
    • https://myclubowners.travelenvogue.com/userfiles/files/31246874833.pdfIn PDF document text
    • http://mawaevents.com/uploads/file/sugidafuwemuzepup.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/vapopiwenegekixel.pdfIn PDF document text
    • http://chixue.com/uploadfile/file/20210903163140.pdfIn PDF document text
    • http://go-pxl.com/uploads/files/72192312487.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/67791243066.pdfIn PDF document text
    • https://internationallanguagenavigators.com/media/86203853942.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_off0000cfea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFEA 17996 bytes
SHA-256: 2bfe2998dc9fc95a7d08a97b0a5062da101447ad12610bde16efae4de695d36f
font_01_sfnt_off0000fe2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE2D 10924 bytes
SHA-256: c5c2417e7cfe69e6f44660887755e9558dbf538eb16686525269db9b898c5c8d
font_02_sfnt_off0001178c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1178C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1