Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c87d8b65dc395d1…

MALICIOUS

PDF

70.1 KB Created: 2021-09-16 08:05:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fa9433208e9caed2d6d6677c2b8bba79 SHA-1: 6db1d5029af91d67c7e2d9ea764a7d9e72fda7b0 SHA-256: 5c87d8b65dc395d1404d37fa42618b17e3969f864d15d0380f2b5509e95ad087
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file that exhibits characteristics of a link farm, with numerous embedded URLs pointing to potentially compromised websites. The presence of embedded JavaScript and a high ML classifier score further indicate malicious intent. The primary goal appears to be directing users to external resources, possibly for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://huntic.ru/uplcv?utm_term=frag+game+download+apk
    • http://uslugi-ogrodnicze.pl/pliki/File/49490959093.pdf
    • http://veewood.com/file_media/file_image/file/63651064834.pdf
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/65183c9fbf0866af42f48da9135aa11a/pofigojikunuwotobazopidiw.pdf
    • http://leebyunghun.org/new/upload/board/files/30162539905.pdf
    • http://technology-mp.it/userfiles/files/73672851382.pdf
    • https://qwert5.com/psum/admin/userfiles/file/wubafojivuwozebofazawuru.pdf
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142b5a82662c---dajinogupewolebapakemobaw.pdf
    • https://u-spot.biz/js/ckfinder/userfiles/files/84722167620.pdf
    • http://www.kickcommerce.com/userfiles/file/timovuponozutabejomemapa.pdf
    • http://stellar-toys.com/ckfinder/userfiles/files/robuwawujikogez.pdf
    • http://shbaicun.com/userfiles/file/2021090120583373499.pdf
    • https://protrialse.eu/files/files/fudini.pdf
    • http://focalthai.com/file_media/file_image/file/64074064226.pdf
    • https://samsungklimamodelleri.com/upload/ckfinder/files/37429069584.pdf
    • http://tecs4.com/intranet/ckfinder/userfiles/files/30931371973.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16134086083789---merizapuvi.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9d03f3ef1---71300109111.pdf
    • http://lagrupacio.cat/file/zopaja.pdf
    • https://parvazyab.com/basefile/api203/files/sogubutofinugu.pdf
    • https://www.gico.ge/ckfinder/userfiles/files/3129733504.pdf
    • https://fundreamz.com/ckfinder/userfiles/files/tebajul.pdf
    • https://dennismaloney.ca/upload/editor/file/52319958455.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b059.bin
928ab69ce07b68d6e7724e65134c96608f0efe5d49233ada4b6f8e668017b8e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB059 10532 bytes
font_01_sfnt_off0000c815.bin
9beffa23e82010d4d97b3a900e4db5c578f0b3d4e79f1719ba49dc4c9788030d
pdf-font-stream PDF embedded font (sfnt) at offset 0xC815 16736 bytes
font_02_sfnt_off0000f333.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF333 16792 bytes