Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8b2f79ab97cd7c9…

MALICIOUS

PDF

85.4 KB Created: 2021-06-29 18:45:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 16213fde53a733e972ef33b0dc97de5d SHA-1: c0950a7ef2f4bb37497f15eec6ab4bff14f50021 SHA-256: f8b2f79ab97cd7c95098a5044edcde39266cf2df85109ae55fa7f89275a9fa53
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with many embedded URLs pointing to external sites, some hosted on compromised WordPress installations. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, suggesting the primary function is to host these links rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://www.albispanaderia.com/wp-content/plugins/super-forms/uploads/php/files/b8e6a583d0356c9da34f5a2faab49c3e/mimekiwazikedevaguge.pdf
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/863ab45ac00c9f1be2b2adcd60c26e7f/50911762525.pdf
    • http://aj-logistics.com/stock/userfiles/file/70731113230.pdf
    • http://blueyee.com/upload/file/240209221081.pdf
    • http://sklepjola.pl/userfiles/file/bevuwabetonuxezu.pdf
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/903c5b03470762d612fbc2bd884fe5ea/10465358297.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ab57e3aa25e---tigozebutubube.pdf
    • http://gandolfiarchitetti.com/userfiles/files/pogevokiriwebejumujekezuf.pdf
    • http://carefirstyoungatheartgala.com/clients/b/bc/bc61c41cf33a111e4089ebab1e34a2ce/File/sanivapelaji.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a65f3442e96---35732916148.pdf
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa40757fcab---puxevaxofanume.pdf
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cfd7ea620da---1147782903.pdf
    • https://brahmagnanam.org/fck_uploads/file/betupogudeliwamakobat.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/d7b051cb00df95eb64256d09e295ca20/38182445101.pdf
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/8e8116d62bbf3cf73905ecee44206632/7643459395.pdf
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/e1vtki20sauc44beqkookf8u9f/36288962768.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098995798362---mifabi.pdf
    • http://billsky.ee/files/file/29535435139.pdf
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/5bdmjgf17hi6nv9e8m69fgnl85/xesen.pdf
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/cae0feda32f52b99992ea6f8ec0cfd97/runazotugomaku.pdf
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/8c457a2b3c65454ab9014a9c74a719cc/wofetavevipuduz.pdf
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160835547b351a---gilupapixom.pdf
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d26df4c8234---movenelemelelugu.pdf
    • http://tipsclubcr.com/campannas/file/96698184107.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=stretch+outer+hamstring
    • 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_off0000ea56.bin
617dd8319cf3ba071565157a561ff16cab8dad16b628182195fbb55b5e6df5e6
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA56 16868 bytes
font_01_sfnt_off0001162a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1162A 16792 bytes
font_02_sfnt_off00012e41.bin
3dffb4d62f515b62fdf8dc1eb75eaf50931554a01ab06cd1096ded705cb9786a
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E41 10808 bytes