Malicious PDF — malware analysis report

Static analysis result for SHA-256 98efb8857f497e7f…

MALICIOUS

PDF

108.6 KB Created: 2021-07-01 22:16:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b26e6cb8373ea16c02c48f968288bdd4 SHA-1: 435da9fab6d53c8a0064bbe99f1dedc02c162748 SHA-256: 98efb8857f497e7f3405a28657bcd6989e4f1ab16465430eaa2d6104978e9e31
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to compromised CMS upload directories, indicating a link farm designed to host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the PDF structure itself is used to facilitate the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/b51c8970d1fa2ff45766e19ba7d816d3/ravobojusonan.pdf
    • http://brilspa.ro/userfiles/file///58161874808.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b46b4d0c2bd---xuripudezomusug.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/b7c96jd6t4njis4hbeoe7m3v44/15692440701.pdf
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160b845ff1070e---guxagalaxaxubonosa.pdf
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607559a969e93---47308760622.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160daec74c5c40---zosiridijujim.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7815448146---62440978034.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607991c72ec84---sizanupogopek.pdf
    • https://chamsocmuihong.com/wp-content/plugins/super-forms/uploads/php/files/t4ksg2u034cj5d1gprs6lf73t9/duluridijetedesedowu.pdf
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/5a42fad1468747130a0875ae51ceae53/20090802195.pdf
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/pv6h70h09b6goanocidpe7q41j/5833999673.pdf
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/2o2dopre546e69qoba84u4q2hd/lupadesivotabigevum.pdf
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe83ccf5ba---surotaz.pdf
    • http://teifsepahan.com/files/file/wikukavumirukelexelew.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bea334c77c4---52319889758.pdf
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a41041c48db---refenegukaxik.pdf
    • https://songuryazilim.com/calisma2/files/uploads/4217996121.pdf
    • http://rauvuonsach.com/images/uploads/files/notepasuralikevibonulub.pdf
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/9e7272706830a8726b35ab48b98c2145/58790793002.pdf
    • http://mhfmjournal.com/data/22/2/55/64/2544879/user/2788947/htdocs/userfiles/file/sogama.pdf
    • https://alternativecarrepair.com/userfiles/file/fojitedifuguturonileg.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=journalists+known+as+muckrakers+worked+at
    • 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_off000145aa.bin
78c8cc70de88efc79a9d82d49d20e123cb85fdb472e9bc4c3a2e1e4d3394454f
pdf-font-stream PDF embedded font (sfnt) at offset 0x145AA 17636 bytes
font_01_sfnt_off000173dd.bin
28c39e760c0715369591dd047976ec87fcde8f9440114a2c4f8c06748e068d20
pdf-font-stream PDF embedded font (sfnt) at offset 0x173DD 10800 bytes
font_02_sfnt_off00018cd4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x18CD4 16792 bytes