Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c974876e4537c7e…

MALICIOUS

PDF

88.2 KB Created: 2021-08-10 08:38:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 91d3e889a8042447af28fd1d93539e78 SHA-1: ad30e140181704c9461195ba97e67d6e85e4f50b SHA-256: 4c974876e4537c7e8cac0ff6342adaf856e569087840ef235db85cb44a1f93d3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm directing to numerous compromised WordPress upload directories and other disposable hosting sites. This pattern is indicative of a phishing or malware distribution campaign, where the PDF serves as a lure to redirect users to malicious content. The ClamAV detection and ML classifier strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ecf5d5043a---84157936686.pdf In PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/gunetiwi.pdfIn PDF document text
    • http://stihoplet.by/upload/editor/files/sunojomulod.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097e24d86aff---15907390544.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/rutefojo.pdfIn PDF document text
    • http://masseydogs.com/clients/f/fc/fc2e217ffa4851e49ca3cd921a15cf41/File/borajedu.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160716aeb3da22---nolawipewunagu.pdfIn PDF document text
    • http://uptownherndon.com/uploads/files/27768901855.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/0r8seqf078bt2tmap71umujfj0/10223927945.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/b1e2f4e3910dabd49c495863a7bcb284/jadodewof.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160771fba5925a---pudazukofer.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1faceb0811---75027743521.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/55549759864.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160868dcfac894---9974908931.pdfIn PDF document text
    • https://morethancleaningservices.com/wp-content/plugins/super-forms/uploads/php/files/2cf28609510b0212293693e296ca2d50/24105945583.pdfIn PDF document text
    • http://kangs78.com/clients/66216/File/vixavobe.pdfIn PDF document text
    • http://bycongroup.com/UserFiles/file/vopimotepivurutap.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///2021050821659_732615074.pdfIn PDF document text
    • http://thailaundry.com/imgUpload/files/siwugizemepazude.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160ee5e1795634---66552834918.pdfIn PDF document text
    • https://xn--80aaijz0c.xn--p1ai/ckfinder/userfiles/files/63594930350.pdfIn PDF document text
    • http://iphysiology.ru/upload/daxiwulerimefovekikat.pdfIn PDF document text
    • http://exito-opakowania.pl/userfiles/file/58697271177.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/filudiketobanoz.pdfIn PDF document text
    • https://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160846709e8871---kuxexebekapukege.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=p90x+plyometrics+exercise+listPDF link annotation
    • 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_off0000f367.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF367 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B79 16924 bytes
SHA-256: 041898997598b88acba09c1690a34cf46dc61088e225d7dcc70352e81bd27b86
font_02_sfnt_off000137be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137BE 10776 bytes
SHA-256: 517c3f1b21f1f3303101d9f22b7b07b297dfb2bb92cd4cbe88a1db8db0c3bd8c