Malicious PDF — malware analysis report

Static analysis result for SHA-256 35724c25f2f85eee…

MALICIOUS

PDF

82.0 KB Created: 2021-09-11 08:59:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dc9b1bc6867bcd76c6211ba4171d36df SHA-1: f91d31c9b77dcb3db26c0dd131eb29a68328459d SHA-256: 35724c25f2f85eee17bfba3a5ae2bc6dbb41ab3eb47de42bc0752eb0d7c716d1
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to potentially compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The embedded JavaScript is a common technique for initiating malicious actions within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://anhuishangbiao.com/upload_fck/file/2021-9-7/20210907060010708753.pdf
    • http://theflowermaker.com/uploads/File/bolafenuzoguk.pdf
    • http://fairfresh.net/assets/admin/ckeditorimage/files/19246607919.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/vcoqlqmgum9ioo66h4m6udjo31/fowizuzo.pdf
    • https://megacook.pt/site/upload/file/95006031756.pdf
    • https://cpc-serbia.org/js/files/supujevivazi.pdf
    • http://hizirferforje.com/admin/fckeditor/editor/images/file/44747329054.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/161352bcb76c28---57446073572.pdf
    • https://wendi101.com/userfiles/file/67900272872.pdf
    • https://daks-96.com/f/uploads/files/94074928047.pdf
    • http://debandhelder.nl/ckfinder/userfiles/files/25282451819.pdf
    • https://xtrafitcoaching.com/www/images/files/diwidula.pdf
    • https://pharma-tools.eu/galeria/file/bogunugidijimekesokupaban.pdf
    • http://safarang.com/basefile/files/muzimozumopexaxitajabepif.pdf
    • https://yarpaket.ru/userfiles/file/nijogizujudejigo.pdf
    • https://underworldgear.com/upload/users/files/15085536388.pdf
    • http://geodavidepini.it/userfiles/files/gowosozezokibodewup.pdf
    • http://kyochonbuenapark.iorderfoods.com/uploads/files/87476530478.pdf
    • http://qianxish.com/ckfind_image/files/50639153118.pdf
    • http://www.dean-cpa.com/files/adminpic/file/22437201916.pdf
    • https://ecoquimica.cl/dinamicos/uploads/file/93528178483.pdf
    • http://cargologicru.com/sadm_files/nikadezat.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be7ac763b0---58465749747.pdf
    • http://gagutp.com/sa_upload/userfiles/file/20210910185621.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=mikandi+apk+gold+unlocked+download
    • 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_off0000dcd9.bin
9fd5a15e2f3c65c6ec541cc5e0298b6a6caa3941d6f30189a127b4ac7b2f9a7c
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD9 17360 bytes
font_01_sfnt_off00010a1b.bin
23f2bbdf9f0e5e137f1c5c33fc19e71af16b9654cd4667e3ffbc6db6e7b65865
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A1B 10596 bytes
font_02_sfnt_off0001222f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1222F 16792 bytes