Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b8f982b1ba9f4e8…

MALICIOUS

PDF

111.6 KB Created: 2021-06-26 03:52:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e988cfb94be826fd1384d77d1a4adaa4 SHA-1: 84b527215290dbd9338332c5003ad6634ace399a SHA-256: 5b8f982b1ba9f4e8200907362fd6f24cdb34162bb3f3fbc0ceb68cfd56313d47
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous external URIs pointing to domains that appear to be part of a link farm, with several hosted on compromised WordPress sites or disposable hosting. The document body is unreadable, suggesting it is not intended for human consumption but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • 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://medvor.ru/uplcv?utm_term=lean+startup+movement
    • http://shsalumniauditorium.org/clients/f/fa/fa32e32112b7cad64a7d7e78b95ed61b/File/rakamitano.pdf
    • https://clumba-indoor.ru/files/files/zodik.pdf
    • https://hssipm.com/wp-content/plugins/super-forms/uploads/php/files/91ceeecc0073477a46142a53adffe798/lemilipadatemixetem.pdf
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/vusj1ut20viajojn823lebrblu/15676462186.pdf
    • http://moscowprice.com/content/xuploadimages/file/waluwuz.pdf
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160afe0f5027e8---diwaxukija.pdf
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/04729ec7da395a95ea92ccbbc62abcb0/lusedoz.pdf
    • http://thuephotocopytaihanoi.com/upload/files/rafaruxolukuremakovoju.pdf
    • https://svarovanijelinek.cz/ckfinder/userfiles/files/79634246335.pdf
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5b0725c14---95924611288.pdf
    • http://kingsfinancialconsulting.com/userfiles/file/84989183609.pdf
    • http://oreade-breche.fr/userfiles/file/jitarupegidozemizilirikev.pdf
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/kjgb49ci1fkp5tgl32bdjm6tlg/81640258289.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/n3s7i2vvrrmvqn6serap0c1m54/40342061874.pdf
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/i0uggphmas0qie8qdi1ktltl83/lovoxoku.pdf
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16076314ceaa97---siwaxorinivupokaxi.pdf
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609dac866f68c---gozofiwo.pdf
    • https://remoteyourstaff.com/calisma2/files/uploads/81674143365.pdf
    • http://aep-tc.com/cache/fck_files/file/lirezinogepojigubo.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16096416ba7e42---49308122464.pdf
    • http://stacjaregeneracja.pl/userfiles/file/misogawutamisuminusisode.pdf
    • http://resetimpianti.it/reset/public/file/lifuripovugapofovim.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fe42be6b3b---81229918543.pdf
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/56d61071a9be7c025988ba1c8fae5008/59066785123.pdf
    • 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_off0001550f.bin
43437a15c11dbc04d8565f069a6fc7632c3d9dea3249f2e4e32487c66847ba70
pdf-font-stream PDF embedded font (sfnt) at offset 0x1550F 10400 bytes
font_01_sfnt_off00016ca2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16CA2 16792 bytes
font_02_sfnt_off000184b4.bin
ea92ec98bfd301e014de10caff581ed9485432888a6df3ababd1d7ebe314267e
pdf-font-stream PDF embedded font (sfnt) at offset 0x184B4 17184 bytes