Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a8754f8ab848181…

MALICIOUS

PDF

84.1 KB Created: 2021-08-04 07:53:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 222408b55255f2f88994c935f4f99d92 SHA-1: f144bf4d4157bcd295b24205fe6ff55e125fe8cd SHA-256: 3a8754f8ab848181898f04e84a5cbfe41381de3fdaf28d3157046136d005ec8f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of embedded JavaScript suggests an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/6da422fc67d1c6fe5b951d5e10adfbd0/nubedotaradajubibarega.pdf
    • http://drukarnia-warszawa.pl/pliki/file/92005604369.pdf
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/78md4j9h5jmqdhrsnsnt9ovdt5/38088518052.pdf
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a3eb50c0251---19659247179.pdf
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160723977c1706---paguwabojalobezepiboneki.pdf
    • https://erdenetpost.mn/userfiles/files/75318311988.pdf
    • http://mackyz7automotive.com/js/upload/files/85655221995.pdf
    • http://oicenglish.com/imagexx/files/13039583126.pdf
    • http://profesniprukaz.cz/ckfinder/userfiles/files/31801054563.pdf
    • http://rentbucharest.net/images/userfiles/sogadisa.pdf
    • http://andreaslasnik.com/data/files/dilizumubebubepiwizur.pdf
    • https://ludifrance.fr/userfiles/file/79443999220.pdf
    • http://magyaringatlanadatbazis.hu/dev/_user/file/vufupoxurabemavobo.pdf
    • http://ibb-online.ru/f/file/burijoxadigor.pdf
    • http://araonline.hu/uploads/file/56176529380.pdf
    • http://allgeology.ru/ckfinder/userfiles/files/warekoz.pdf
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160718b717cfcc---nanerabofaso.pdf
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7e33a9f76d---zopoxivuzopinuwezi.pdf
    • http://goldmustang.com/files/files/nekesifibotoro.pdf
    • https://steklo-shik.ru/userfiles/file/nikikumore.pdf
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b76eb93fda4---80897744342.pdf
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160b8086376454---6298308782.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=cuadernillo+de+actividades+de+matematicas+para+tercero+de+secundaria
    • 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_off0000dc60.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC60 16792 bytes
font_01_sfnt_off0000f477.bin
82c5979255062be192516d99b714aca3b424960499f82079af2ff26e67151918
pdf-font-stream PDF embedded font (sfnt) at offset 0xF477 10872 bytes
font_02_sfnt_off00010d92.bin
37e86d2903ddc4f334843264a0a6bbe12318b02a387fa74410f7837b6d4e9d6d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D92 20356 bytes