Malicious PDF — malware analysis report

Static analysis result for SHA-256 555550c4d58f7ff8…

MALICIOUS

PDF

87.3 KB Created: 2021-09-17 21:11:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6b72fb4f4a0c717dff60fea843e22730 SHA-1: cea7a6c55b58841a54a8c287a161f5aef542cb83 SHA-256: 555550c4d58f7ff81c3ff36f7a7c500e815ee16f1aff4b32a5dc70f55890bc86
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV detection. It contains numerous links to external websites, many of which appear to be part of a link farm hosted on disposable or compromised domains. The presence of 'utm_term' parameters suggests an attempt to track user interactions, common in phishing or scam campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://infrive.ru/uplcv?utm_term=how+to+see+hidden+apps+on+android PDF link annotation
    • http://el-master.ru/userfiles/file/21238406079.pdfIn PDF document text
    • http://prefinancovaniehypoteky.sk/res/file/39211572343.pdfIn PDF document text
    • http://www.focitabor.hu/userfiles/file/81805614117.pdfIn PDF document text
    • http://hanilkwanla.com/uploads/files/80789617479.pdfIn PDF document text
    • http://habitat3.eu/userfiles/files/76890532034.pdfIn PDF document text
    • http://sartoriaventurini.com/userfiles/files/teguxidavuzijal.pdfIn PDF document text
    • https://millersexpress.com/userfiles/file/84159584469.pdfIn PDF document text
    • http://jn-zhsc.com/upload/larojurekotivexumoxeput.pdfIn PDF document text
    • https://condominiovillage.com/userfiles/file/80495194762.pdfIn PDF document text
    • http://metamorfozyayincilik.com/userfiles/file/84289278579.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/sedomaxudejegumewap.pdfIn PDF document text
    • https://www.wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/32929721294.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/xewefuzorawezozepopiduz.pdfIn PDF document text
    • http://tbff-bygg.se/img/files/19442809457.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/1d2933e2081b31b60de793d13f0b8397/tefab.pdfIn PDF document text
    • https://lyna-garage.com/htdocs/cljr/data/files/nemuruno.pdfIn PDF document text
    • https://betenrealestate.com/sites/default/files/file/tosidonamode.pdfIn PDF document text
    • https://askisan.com/upload/ckfinder/files/navibakipadipuwute.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/19268166414.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/16133c4056c348---12363893412.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132ad66a9e5c---54434635613.pdfIn PDF document text
    • https://alwillislifecenter.org/ckfinder/userfiles/files/5302145378.pdfIn PDF document text
    • https://imihwa.com/uploads/image/20210911/files/20210911085727.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_off0000f108.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF108 10520 bytes
SHA-256: 18146afb5a8f52df4cdaa48c89a87d7f73dc097177f77686a8a61805d9a023fd
font_01_sfnt_off000108f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012108.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12108 17892 bytes
SHA-256: eefbcbf4ebf305b67868e604fbff7e13df1885d8b7b762adece3e3b3773314d6