Malicious PDF — malware analysis report

Static analysis result for SHA-256 939f4c4bdf4872b2…

MALICIOUS

PDF

88.5 KB Created: 2021-09-10 03:56:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: 2d5e53eccf7f173c2f0c7aee27bd1511 SHA-1: b5fe27aef646ffcde856ab6f8d0daa72c2cbb2c3 SHA-256: 939f4c4bdf4872b258d61b7e63dfaa6e74453ff95ea090b72c2f84ae17399b0c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of techniques used to deliver 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 https://smidgel.ru/uplcv?utm_term=minecraft+pocket+edition+latest+update PDF link annotation
    • http://salman-is.com/userfiles/file/jofewugemimapajamujekubi.pdfIn PDF document text
    • http://tucsokszekszard.hu/images/news/file/gotawixikomujanidexow.pdfIn PDF document text
    • http://zhongguohuachun.com/d/files/muxefevedixajerasolojuxu.pdfIn PDF document text
    • http://superlitefan.com/uploads/files/jejojakimefobirejezarovi.pdfIn PDF document text
    • http://pcwenhua.com/uploadimg/file/1630676172706995895.pdfIn PDF document text
    • https://inks.bg/userfiles/file/kizodesagokalozu.pdfIn PDF document text
    • http://yejida.com/userfiles/file/pazimasaxutubijobo.pdfIn PDF document text
    • http://myconnect-thailand.com/image/upload/File/37151763588.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/a0fac74210e0381c0f34bb5ebc85a81f/42083879040.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/pvld9memu5uvpcnvrb1g8hbvdj/53856996829.pdfIn PDF document text
    • http://lawyergz.net/uploadfile/files/gijenixexufirit.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/11475948950.pdfIn PDF document text
    • https://indirimlipin.com/calisma2/files/uploads/besenumiguwov.pdfIn PDF document text
    • http://jinsonmetal.com/Upload/file/31023551342.pdfIn PDF document text
    • https://brianspradlin.com/userfiles/file/zelidinavibatawuketup.pdfIn PDF document text
    • http://vietsonplastic.com/uploads/userfiles/file/sazejufelerori.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/2ba32b337b803b17699254d80cb866f9/fabujuxorizug.pdfIn PDF document text
    • https://98ing.com/upload/ck/files/20210902_233842.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF99 19968 bytes
SHA-256: 8215c5ee3281e30c3b01db1a4655fb3d2291541f69bed04def8bb661f31e981d
font_01_sfnt_off0001240d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1240D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013c24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C24 10800 bytes
SHA-256: 9a33d17c559f309b9fa7634bc81862d3085729403ab7a6023b7ee1dd599dddfc