Malicious PDF — malware analysis report

Static analysis result for SHA-256 756c9f3f4be89526…

MALICIOUS

PDF

107.1 KB Created: 2021-10-06 13:29:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: ccdbb731608d72d9791883e6fe530534 SHA-1: 01c8a31a9e43502250ce96a2c3c7b1dd826e5585 SHA-256: 756c9f3f4be89526111f633fca46e00315fbb383efa2fdf85f7248be4a078a7d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to disposable hosting and are likely used for phishing or distributing further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan. The document body is unreadable, but the heuristic firings and numerous URLs are sufficient to infer a malicious campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://laborke.ru/uplcv?utm_term=definition+of+communism+and+socialism PDF link annotation
    • http://preciz.com/uploads/wysiwyg/files/5432987070.pdfIn PDF document text
    • http://stickerbarcode.com/file_media/file_image/file/sixizineveserawo.pdfIn PDF document text
    • http://chanassociation.org/uploads/file/37053967027.pdfIn PDF document text
    • http://ski-experience-japan.com/images/blog/file/mawefelumikulonefej.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16158a9ff5f721---doxivadapo.pdfIn PDF document text
    • http://srldirect.com/ckfinder/userfiles/files/sagunujumixerowunovikozux.pdfIn PDF document text
    • https://dogathermalhotel.com/resimler/files/zumoxugaruzajazivuxat.pdfIn PDF document text
    • http://betheaskssd.com/flash/betheaskssd.com/file/jedivipi.pdfIn PDF document text
    • https://sharjahcements.com/images/bulk_images/files/29955104195.pdfIn PDF document text
    • http://acm-medicali.it/userfiles/files/6114542810.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/mibimulonenoxulatapovudi.pdfIn PDF document text
    • http://qlionshousing.ca/userfiles/file/44065791075.pdfIn PDF document text
    • http://sungder.com/upload/36745515937.pdfIn PDF document text
    • http://e-junghan.com/userData/board/file/ligas.pdfIn PDF document text
    • http://tugrabilgisayar.net/resimler/files/62485388215.pdfIn PDF document text
    • http://lauko-baseinai.lt/i/File/domidafudukugewadizafat.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/90rh1b1h25b1lvar117o9iakd2/mavobosoviwixeka.pdfIn PDF document text
    • http://qianxi.cn/filespath/files/20210921012046.pdfIn PDF document text
    • http://acunambalaj.com/adenoto/upload/files/lexobitovitukurute.pdfIn PDF document text
    • https://data-face.noithattoantam.vn/userfiles/file/37347957997.pdfIn PDF document text
    • http://www.gieskestukadoors.nl/ckfinder/files/files/monire.pdfIn PDF document text
    • http://audyt.rowerowaszkola.pl/imgturysta/files/62180975664.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_off000138d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000150ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x150EA 20480 bytes
SHA-256: 745efed71c9f17b1e5369e264e2a5fc79ef464367a2dd65b5dad38136262a6b7
font_02_sfnt_off00018647.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18647 10640 bytes
SHA-256: 4d1f06a5ee5aca5c0adb5bb8704fbdc6a0802fc3d47855c7df8779eb7bbf2d71