Malicious PDF — malware analysis report

Static analysis result for SHA-256 f91ddb3f897e390a…

MALICIOUS

PDF

84.9 KB Created: 2021-09-14 14:49:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f1525151edd33af104801770faf69dfb SHA-1: 43c2209cb50a668bbe94b24206ad2d6cd82a1616 SHA-256: f91ddb3f897e390ae34a3a8991960d1421e2c6f110f602a2dcaacee237362ea3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious documents that may leverage embedded JavaScript for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://pistant.ru/uplcv?utm_term=tv+television+apk PDF link annotation
    • https://groupburuemas1.com/contents/files/21322560761.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/161378f6468648---9490708727.pdfIn PDF document text
    • https://dom4m.by/userfiles/files/guxupukox.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/jilamitakisewuwumibakaze.pdfIn PDF document text
    • https://pilot-nav.com/ckfinder/userfiles/files/70428998898.pdfIn PDF document text
    • https://paidionresearch.com/userfiles/files/kuvowoguxutawofevopegol.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/40473840408.pdfIn PDF document text
    • http://nsfeed.com/_UploadFile/Images/file/64826591494.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/sigalixivemof.pdfIn PDF document text
    • https://regenerateacademy.com/file/12110450427.pdfIn PDF document text
    • http://i-tos.com/userData/board/file/voxiki.pdfIn PDF document text
    • http://merklink.nl/site/data/ws/files/fodawuzekuwasaf.pdfIn PDF document text
    • http://imosa.asia/uploads/files/202109082129592682.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/5v47e8n7m24jp2c004pmrc49b9/dadopivufiginukole.pdfIn PDF document text
    • https://matratva.in/userfiles/file/jemifoturibefo.pdfIn PDF document text
    • http://www.prakashirrigation.com/uploads/fck/files/burupafumizufa.pdfIn PDF document text
    • https://itracmediav5.com/ckfinder/userfiles/files/22030466667.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/xojojimegetorixujudavum.pdfIn PDF document text
    • https://grouptm2.com/contents/files/xikafoxegajimomoroxaxewo.pdfIn PDF document text
    • http://jlicentral.com/images/authors/file/xinapujadidenakewi.pdfIn PDF document text
    • https://12waktu.com/contents/files/94677957778.pdfIn PDF document text
    • http://hondaototanan.com/upload/files/45429720920.pdfIn PDF document text
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/b684667ba26190b330a606386271bd2d/pomonu.pdfIn PDF document text
    • https://creteservices.com/FCKeditor/userimages/file/katinewoxigijux.pdfIn PDF document text
    • http://himalayakebab.com/shipinc/userfiles/files/89508779338.pdfIn PDF document text
    • https://bhandarisurgical.com/ckfinder/userfiles/files/duvewegawisarube.pdfIn PDF document text
    • http://mebelhotel.ru/userfiles/files/58555015836.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_off0000e6e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6E1 18212 bytes
SHA-256: 1b4d76c29c68c1ee45d3de413cd91bd78fa6b28da3968e405f9e3b0d7dad681c
font_01_sfnt_off0001169c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1169C 10268 bytes
SHA-256: 04fe899bb9da009960d7180650d2f0da8dcb2f80792e6798c0bef70d6c6e5f8c
font_02_sfnt_off00012de3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1