Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf841a1be1b4f9c9…

MALICIOUS

PDF

79.6 KB Created: 2021-08-09 12:28:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 48112bec860b8adcfd9d61aff78f89f9 SHA-1: 5ae9440ca5148f0368a3f506f0a2fd41927bd7c4 SHA-256: cf841a1be1b4f9c9b03a963b670c8461234e15a4ecfdda08c785cb5cc770976e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, indicating a link farm designed to redirect users. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to exploit users by directing them to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://easternsheep.by/app/upload/file/tavezajomamigatosuzod.pdf
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b2570b3695e---36767860359.pdf
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/980550184f4ea158c5848e0771e41f91/22754579619.pdf
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/ca3dd05bb72171f68e10359d6d9ee78d/mobobezowulejo.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab86db175c---62413176836.pdf
    • http://xn--80aaffebba2apgigwiiececnggk9e4k.xn--p1ai/pict/file/76318794459.pdf
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bce2783b27d---mosorewisegivilevegapul.pdf
    • http://alituncer.com/userfiles/file/24392497940.pdf
    • http://zhodnoceni-penez.cz/is/images/FCKeditor/File/51470318064.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/78babf9da8518d6ef7159a7a9ccfd249/sozojigi.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609a7de3618ba---lunalorarar.pdf
    • http://mxm-hosting.nl/img/editor/file/72824488648.pdf
    • http://daydreamspin.com/userfiles/file/30425672571.pdf
    • http://meteosputnik.ru/userfiles/file/16744334849.pdf
    • http://braciszewska-klimek.pl/fck_files/file/nugoro.pdf
    • https://ctapigroup3.com/contents//files/48279374255.pdf
    • http://www.cafeinca.com/img/public/contenido/file/wagenejavufuremaxuda.pdf
    • https://pakistanchristiancongress.org/userfiles/file/94912443738.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa496e8d07c---napiwomukozirasibelu.pdf
    • http://omegapizza.net/uploads/files/93428265443.pdf
    • http://beergolfers.com/blog/images/file/21511310056.pdf
    • http://lovesenergy.com/file/zososepugibaxa.pdf
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/kqkntrtntfdnopevebt98h9gjr/7732976645.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=saxon+math+intermediate+5+pdf+section+3
    • 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_off0000d309.bin
2b7611619e6ccf8bed6587cf3e3a7a8a27e06483fe820ecebca24bf82cbe8a52
pdf-font-stream PDF embedded font (sfnt) at offset 0xD309 16976 bytes
font_01_sfnt_off0000fdc1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC1 16792 bytes
font_02_sfnt_off000115d8.bin
62494f2e8a52b92e873219395cd5dfd49ec1bbf8fb7ab2e814435b2ede5c1050
pdf-font-stream PDF embedded font (sfnt) at offset 0x115D8 11324 bytes