Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5045202fe30a1e4…

MALICIOUS

PDF

82.0 KB Created: 2021-09-19 22:10:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: dd5c84daceb2d0e48159d69c166b204f SHA-1: 439d29e27b6eaf26e1d146d9bd57fc15f33e2790 SHA-256: f5045202fe30a1e4139bcc76343776605c0f979041bc8f1f2263ca2e917243ec
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to domains that appear to be part of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is the primary function. While no scripts were extracted, the ML classifier and the nature of the URLs indicate malicious intent, likely to manipulate search engine results or redirect users to malicious content. The file's creation by wkhtmltopdf suggests it might have been generated programmatically for this purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 4

  • 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 http://banlinhkienlaptop.com/userfiles/file/mazufigurozakesowov.pdf In PDF document text
    • https://forumsevens.com/images/file/tebitaxo.pdfIn PDF document text
    • https://eclearusa.com/images/file/13560239756.pdfIn PDF document text
    • http://checopharma.com/upload/files/99408222076.pdfIn PDF document text
    • http://candybeauty.vn/upload/files/77985864559.pdfIn PDF document text
    • http://ned.ru/uploads/files/91488523936.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/95439046471.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/ec35558135eb340f0ab0ff26996c49ed/buvapozenamaxefifukekipax.pdfIn PDF document text
    • http://muzycznescyzoryki.pl/userfiles/file/ramusulufudafubu.pdfIn PDF document text
    • http://jatyn.cn/upfiles/202109/file/1631444293.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/fcv3cfcirgmsfnmh5jjmhg1bv2/71786427939.pdfIn PDF document text
    • https://eagle-aviation.com/userfiles/files/23013557114.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/jenamewemovisivevetafi.pdfIn PDF document text
    • http://xn--c1aejbdnke.xn--p1ai/admin/ckfinder/userfiles/files/regikudigi.pdfIn PDF document text
    • https://siriusdynamics.com/assets/uploads/files/98953154120.pdfIn PDF document text
    • https://vpmemorial.net/images/file/petet.pdfIn PDF document text
    • http://myjobcareer.net/userfiles/file/2021090506091073499.pdfIn PDF document text
    • https://slide-bearing.com/d/files/71665171284.pdfIn PDF document text
    • http://horvathortho.hu/tmp/bijarap.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/28222513886.pdfIn PDF document text
    • https://mitrasuksesku.com/userfiles/file/xurodaxajesigodokavikus.pdfIn PDF document text
    • http://cl-pub.com/files/files/riwukosuxezotume.pdfIn PDF document text
    • https://recapress.com/ckfinder/userfiles/files/91073720416.pdfIn PDF document text
    • https://sfeerweter.nl/userfiles/files/73071437877.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=onde+baixar+jogos+android+gratisPDF link annotation
    • https://easyown.ddproperty.com/datas/files/43066125948.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_off0000d821.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD821 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f033.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF033 19396 bytes
SHA-256: d538d03fad0a17d23043f049686b9710852079924bf0f181c324ef4347772ff6
font_02_sfnt_off00012083.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12083 10776 bytes
SHA-256: c651ab41ac447f3864e751d7d893690893d925216d1a5374ab62300951e30952