Malicious PDF — malware analysis report

Static analysis result for SHA-256 a71827aba6648baa…

MALICIOUS

PDF

86.2 KB Created: 2021-09-24 08:15:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 070b65a71b10b726eec1803c751adf9e SHA-1: f6eb848d193a6b4141424301357ccd1b68ab4cdd SHA-256: a71827aba6648baaed484291e9c621ac05e795b490a0aa032d665da34740eb10
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a significant number of external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm. The ML classifier also flagged this PDF as malicious. While no scripts were extracted, the structure and heuristics suggest the primary purpose is to redirect users through a network of URLs, potentially for SEO manipulation or to serve further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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 http://plaschke-partner.com/uploaded/file/joraxosetugusesijunewisa.pdf
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16143b5f59f0d2---71144682100.pdf
    • https://marugame.hk/editor_upload/file/18774216562.pdf
    • http://cochemical.com/upload/files/97757561617.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16142523351362---ruwakipegifalotug.pdf
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/gupuzat.pdf
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/kopemosuj.pdf
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b6508902ed---81118964262.pdf
    • https://sunrise-photon.com/upfiles/editor/files/83824702844.pdf
    • https://i-try.tw/upfile/files/2021/09/12/28776348373.pdf
    • http://c2r.su/uploadfiles/file/2021091400550773499.pdf
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161468b9768122---dasexav.pdf
    • http://tdjl.com/uploadfile/file///2021090319024421.pdf
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/g3kbkn1ppgg8isoi6fki97cr73/wigafajedorafi.pdf
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/161306cea66a07---dafapejobokuwe.pdf
    • http://aquamedia.cn/ckfinder/userfiles/files/zokiwul.pdf
    • http://xn--o79av69abka850ab6c.com/upload/file/202109160129107901.pdf
    • http://xn--brneneskontor-landsforening-b0c.dk/userfiles/file/85905517329.pdf
    • http://bsp-oblspl.org/ckfinder/userfiles/files/45031148434.pdf
    • https://actsonics.com/uploads/files/202109071049237795.pdf
    • https://energooptima.hu/upload/File/kuwitukapekajesuronus.pdf
    • http://pazarziraat.com/userfiles/file/jebozijewivozafodu.pdf
    • http://herium.net/FileData/ckfinder/files/20210911_93791E633B5F4E18.pdf
    • http://cathyknightwaite.com/ckfinder/userfiles/files/ribasiwulozofudevepi.pdf
    • http://fundacionecla.org/resources/original/file/dobabeleleniwidil.pdf
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/747bbc67ef763f2412dd19ffa2c57873/xafewubijokigidax.pdf
    • http://clairerolo.com/userfiles/file/rofulituxasatunudisokap.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139c78bb52ff---30927240718.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=best+video+editing+app+for+android+instagram
    • 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_off0000ef4a.bin
eaf7b6621eda414125356486a3eb315b1d9c84156cd86ebdf5277cf02b056473
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF4A 16236 bytes
font_01_sfnt_off00011928.bin
0829c570cbe0dc813f7778466a484879379c091e3e9bc3751eca585c74d6c79c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11928 10912 bytes
font_02_sfnt_off00013248.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13248 16792 bytes