Malicious PDF — malware analysis report

Static analysis result for SHA-256 1e3154d26226c8d4…

MALICIOUS

PDF

76.4 KB Created: 2021-09-18 09:10:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a947dab06642423c753fb8a97786a258 SHA-1: c5cb77f99f1ffccc09fc0a0940840f62c2da1e4d SHA-256: 1e3154d26226c8d43562fbdf9c899df6d063146a82778c3106164fdbe9347d6c
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to PDF files hosted on compromised CMS upload directories. This suggests the document is designed to act as a link farm, potentially for SEO poisoning or to distribute malicious payloads. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://impulsa.mantareys.net/uploads/plantillas/files/15750850085.pdf
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131495f41faf---29976992709.pdf
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/d33cd9b6a4b533b85efbe2fcd29cd475/sugujujupid.pdf
    • https://gadd-asso.org/userfiles/file/10425449083.pdf
    • http://cuacuonnhaxuongbinhduong.com/upload/files/37481333620.pdf
    • http://baove24h.info/upload/files/xebutu.pdf
    • https://terracell.pt/images/file/48100784419.pdf
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/ca28965b145a9f853440dc2c619c84da/rovuzutiwezojukalomukal.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132faef7a18b---kozigakanazelupiv.pdf
    • https://ctcitsupport.com/media/files/63057555071.pdf
    • https://insp.biz/img/file/xogafikiwusepomomororitu.pdf
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/b027f28ed2aaa08fa4006cf4d4f1581c/todij.pdf
    • http://izumrud38.com/ckfinder/userfiles/files/zedalopojofu.pdf
    • https://samavetpharm.com/userfiles/files/74406538092.pdf
    • http://cistenivytahu.cz/upload/file/7552637480.pdf
    • https://winstar-tools.com/UserFiles/editor/file/fopupeguvitasogi.pdf
    • http://handinks.com/ckfinder/images_store/files/26809671109.pdf
    • http://pspectr.ru/userfiles/file/85379986014.pdf
    • https://drddvichitra.com/userfiles/file/nudugila.pdf
    • http://zulaikhatextile.com/userfiles/files/56360137745.pdf
    • http://cmtdental.com/upload/ckimg/files/34328034594.pdf
    • http://ms-beauty.com/ckfinder/userfiles/files/zaxiwovapetasutofazo.pdf
    • https://rajaketiga.com/contents/files/97166771601.pdf
    • https://akrmedia.no/ckfinder/userfiles/files/jizudexuxabumuv.pdf
    • http://yaqeen-eg.com/userfiles/file/kuxoviwubupodowexumugepig.pdf
    • https://hw-power.com/uploads/ckfiles/files/613a3e15e1798.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=test+of+divisibility+of+8
    • 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_off0000c236.bin
85fc2e6abe769d1b05866c8b2ca0b9d92fea64f3021cee7c48383613a1d670d7
pdf-font-stream PDF embedded font (sfnt) at offset 0xC236 19136 bytes
font_01_sfnt_off0000f414.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF414 16792 bytes
font_02_sfnt_off00010c2b.bin
d281b9ae298652b4d6f8f91bd4f202466132e516e484b95ec8f773289b207cee
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C2B 10472 bytes