Malicious PDF — malware analysis report

Static analysis result for SHA-256 28609cbe519feb89…

MALICIOUS

PDF

71.8 KB Created: 2021-09-09 11:52:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 80ee5445516dde095ae300ef0defdbc0 SHA-1: 9aba8384295bd81861cf8b914fa942ac77cb8f3d SHA-256: 28609cbe519feb8928639fc9e83d7523c8d155e2453e4b49184f04aaa9ee821a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

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 https://nvsrolko.org/ckfinder/userfiles/files/gojaluxulugozigidej.pdf In PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/57705973405.pdfIn PDF document text
    • http://millionsdiscount.com/mo_images/files/27091913723.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/39f76536695f112c597e29d76f432137/bamilomotu.pdfIn PDF document text
    • http://parfumerieindex.nl/images/uploads/71669572294.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/79543a0dfdbb61bd51cec370dbfc9539/funegezubipedunal.pdfIn PDF document text
    • http://yarpb.ru/pic/userfile/63486908763.pdfIn PDF document text
    • http://divorce-difficile.fr/userfiles/file/kudumovuditepaso.pdfIn PDF document text
    • https://bio86.net/userfiles/fichiers/92224895382.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/mf29aarqtsh20c8snkqsrirkjl/5348661264.pdfIn PDF document text
    • https://journeywithmypet.com/ckfinder/userfiles/files/8049736277.pdfIn PDF document text
    • https://veaodaibrahma.com/uploads/image/files/24532952285.pdfIn PDF document text
    • http://pm-ural.com/uploads/files/sikafir.pdfIn PDF document text
    • http://novastal.pl/userfiles/file/wuseletudepozogunagul.pdfIn PDF document text
    • https://www.mmgrowersg.com/ckfinder/userfiles/files/fupodilopikuzepamakepixed.pdfIn PDF document text
    • https://elearning-chemistry.ro/userfiles/file/nazadapajabagazujerisivo.pdfIn PDF document text
    • https://qfuse.it/images/uploaded_files/ckfinder/files/1630863443_8b4ce85c7b.pdfIn PDF document text
    • https://officialbacknumber.org/editor_up/sabuwifulerivafefaled.pdfIn PDF document text
    • https://boyanbolyarski.com/userfiles/file/vulufazususimixoxep.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/50463925518.pdfIn PDF document text
    • http://lex.tj/img/file/botilutuninixilev.pdfIn PDF document text
    • https://niboparis.com/upload/fckeditor/file/1631135854_1.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=android+ui+templates+source+codePDF 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_off0000b8e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8E4 15552 bytes
SHA-256: e91490febae3c00004ae73bece1a517cca41d3d2c90100cf1081f6ba0dd14ddd
font_01_sfnt_off0000e079.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE079 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f890.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF890 10756 bytes
SHA-256: aa62ad65640edcf1f8bfc93e228cf50326f6152e12c1014e05046da12cff5d49