Malicious PDF — malware analysis report

Static analysis result for SHA-256 99803ac7fb7488a4…

MALICIOUS

PDF

89.1 KB Created: 2021-07-01 16:53:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e9dc72cbba99e775aeb109339845ff5f SHA-1: 72a19ebf241b78835a46b9b06f49ab07a732bcd5 SHA-256: 99803ac7fb7488a42fa66602b000500c8590dc0bdae674dd937e109d4ebc1376
156 Risk Score

Malware Insights

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

The PDF document contains a link farm pointing to multiple compromised WordPress sites, which in turn host further PDF files. This behavior is indicative of a phishing or malware distribution campaign, likely initiated via spearphishing. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b22f3bb50ed---97850334491.pdf
    • https://negaratoto.com/contents//files/30488185815.pdf
    • http://otvorene-srdce.sk/userfiles/file/mowagavemamin.pdf
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a5fc0923cae---12486169778.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ed7e3bb738---tetegas.pdf
    • http://cedule-plachty.cz/files/file/buxado.pdf
    • http://unsersohn.ch/images/file/98634962837.pdf
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/7954a71fbc4d8d61c545fe475e0ae1d3/22340710411.pdf
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c3c44df4228---kososi.pdf
    • https://atlastoursntravels.com/userfiles/file/28660188734.pdf
    • http://beerskiboot.de/img/upload/file/79998459315.pdf
    • http://ajtoablakcentrum.com/_user/file/rotajaro.pdf
    • http://anhuishangbiao.com/upload_fck/file/2021-5-23/20210523220126105297.pdf
    • https://nbtele.com/en/cache/fck_files/file/2978071307.pdf
    • http://cdwy028.com/uploadfile/file/20210524013212.pdf
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/6907mantg2ck09hl6grlno83e6/givufosodebafizefizezosax.pdf
    • https://anjingliar.com/contents//files/25968067994.pdf
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/4755a006a5f10810498007848248b75b/vewudawirog.pdf
    • https://carpanea.it/wp-content/plugins/super-forms/uploads/php/files/a89e018f23898bb782128a37206fbfe8/69233703058.pdf
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160b2f6e011d01---90465021350.pdf
    • https://kodcomputers.ro/2664/uploads/61591784692.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/387isc9ednfs37c9nac8m3ntkr/23068654104.pdf
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bacb60c0019---91666152699.pdf
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/160baf11a4bae2---27288120154.pdf
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160bf8a8d5c03b---mekofujakag.pdf
    • https://darkoyunpin.com/calisma2/files/uploads/benupolitexisomimet.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=how+many+combinations+can+you+make+with+a+rubik%27s+cube
    • 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_off0000f7a5.bin
e1150d476c62ed59a782dead0d52ef35944d48066342c6f74f7b958b52ff1bba
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A5 17560 bytes
font_01_sfnt_off000124c4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x124C4 16792 bytes
font_02_sfnt_off00013cdb.bin
f2f27f05b6dc0ac9b33b56b4bfa1edd239df9779b68fea960ee18b4baa1fcd3b
pdf-font-stream PDF embedded font (sfnt) at offset 0x13CDB 11008 bytes