Malicious PDF — malware analysis report

Static analysis result for SHA-256 873f1c257b6d5241…

MALICIOUS

PDF

76.9 KB Created: 2021-09-09 21:16:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ab27f994ca102061da18067f1bd733ad SHA-1: c16e11327ce57c76ac90da6e73fa5e283cbf64fb SHA-256: 873f1c257b6d5241d0879d7593d0b44ecd581cddba70f0490b665ed28e3b135b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://catamma.ru/uplcv?utm_term=how+do+you+clear+the+cache+on+your+phone PDF link annotation
    • http://e-junghan.com/userData/board/file/vasamo.pdfIn PDF document text
    • http://flynewsletter.com/uploads/file/97355592942.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/rqj48bscuidgrpfqjhlgh07sn6/bexisu.pdfIn PDF document text
    • https://lemarko.com/userfiles/file/dujojut.pdfIn PDF document text
    • http://avtrak.ru/ckfinder/userfiles/files/sewovu.pdfIn PDF document text
    • http://ormansagszive.hu/upload/file/nutoratunobenotovoba.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/72806584616.pdfIn PDF document text
    • http://stonestudio.pl/files/upload/file/gazulizini.pdfIn PDF document text
    • http://china-miyaco.com/img/file/2021930156.pdfIn PDF document text
    • https://equalland.com/uploads/File/delegifavelerawezus.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/e443f2296a283e48cd387a1828687ce2/latozifuzagono.pdfIn PDF document text
    • http://vindindex.nl/images/uploads/64092948637.pdfIn PDF document text
    • http://1night2daytour.com/ckupload/files/56969002481.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff706bf8ca---lotapazodavolenedawerebab.pdfIn PDF document text
    • http://atrsara.ir/resource/files/keripunarudaxinonuxiviliz.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f01dd6acab---sagifi.pdfIn PDF document text
    • http://ndc-group.ru/uploads/files/61321344970.pdfIn PDF document text
    • http://topbuild.net/content/xuploadimages/file/xudozumumuro.pdfIn PDF document text
    • https://curtain.jinware.com/upload/files/12657433619.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/1aef2f0df1a8956cf5c0ba0b73366774/wegegefolixiv.pdfIn PDF document text
    • http://fra2ange.it/userfiles/files/negasajimev.pdfIn PDF document text
    • http://alrehabourhome.com/userfiles/files/pakamibulimigesupufiwil.pdfIn PDF document text
    • https://balaji-technology.com/userfiles/file/kexalamavixevexojefam.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_off0000c97b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC97B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e192.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE192 10640 bytes
SHA-256: f939a3fac932013e05a91f8599ab9b2c793a2d1e8841005889f05d7ea331ba96
font_02_sfnt_off0000f9eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9EB 16948 bytes
SHA-256: b9417429baab663cf77a0b50b2d56c8bb0af7ecbbe8e38869f5d9e7e9a5e3c0b