Malicious PDF — malware analysis report

Static analysis result for SHA-256 e629717831fa2801…

MALICIOUS

PDF

68.9 KB Created: 2021-09-27 04:45:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8896134ea19f2cf7b72726a473903e2a SHA-1: cea7ba8c565dacc2c78d5b65b4b905f62b18fe6b SHA-256: e629717831fa2801fb0d809d4f0019b708370905af4458223cea784e869de2dc
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. The primary purpose appears to be redirecting users to external sites, potentially for SEO spam or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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://auf.vn/wp-content/plugins/super-forms/uploads/php/files/h9816l093lnqm0r661aecap963/revezesakikev.pdf In PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/32a19246a8bcacd045308e4f50e2d134/51722023294.pdfIn PDF document text
    • https://aviatroglo.fr/IMG/file/nezugeripuxaxeleduge.pdfIn PDF document text
    • https://ethnicminorities.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/lepaxexagoke.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/161413a2d97dd9---sanixoxare.pdfIn PDF document text
    • http://originalavto.ru/userfiles/file/81305780859.pdfIn PDF document text
    • https://kungfuclasshongkong.com/louis/taichi/ckfinder/userfiles/files/xujeseretut.pdfIn PDF document text
    • http://kht.civilkozpont.hu/uploads/file/kebusubupijuruginom.pdfIn PDF document text
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/vawawurezi.pdfIn PDF document text
    • http://ytovietnam.net/ckfinder/userfiles/files/buxokepofupizinikupepuv.pdfIn PDF document text
    • http://s2ipower.com/survey/userfiles/files/ropajekumoxu.pdfIn PDF document text
    • http://osayit.com/images/file/4893714462.pdfIn PDF document text
    • https://familienbilstrup.dk/userfiles/file/soxisu.pdfIn PDF document text
    • https://lostfoundglobal.com/userfiles/file/joluxowela.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16138d906ad1d7---31206880787.pdfIn PDF document text
    • http://dietaltop.com/userfiles/files/xujemogezili.pdfIn PDF document text
    • https://evabizz.com/userfiles/file/77695482740.pdfIn PDF document text
    • http://dongzzang.com/userfiles/file///gusukekalukonunedu.pdfIn PDF document text
    • https://ka-base.no/images_students/files/fuvalukirofiwuzipeli.pdfIn PDF document text
    • https://laatjehuisweerstralen.nl/upload/file/serotetokek.pdfIn PDF document text
    • https://gift2goa.com/ckfinder/userfiles/files/94718580985.pdfIn PDF document text
    • http://ghinelliarchitettura.it/userfiles/files/27911346333.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144654f68af1---puvaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=choices+how+to+get+free+keysPDF link annotation
    • 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_off0000af6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF6D 15060 bytes
SHA-256: c4fcac3e97c1e173ebd7ac54739972cbe7c2107396578a04019a786af0fae150
font_01_sfnt_off0000d576.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD576 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED8D 10628 bytes
SHA-256: fdd7b11a001df716711160d2cbeaae76beb48753157b1620414b73d6342ba8eb