Malicious PDF — malware analysis report

Static analysis result for SHA-256 a750b2b1f876f91d…

MALICIOUS

PDF

80.3 KB Created: 2021-09-17 18:32:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d743a27cef6e1c7421d0756eae9e7f4d SHA-1: fbbdaaa2c716fe055fd0ef485e3fe39d3bef1f26 SHA-256: a750b2b1f876f91d36b2055a5357c52f0806567893a1f2f2a395609f80168025
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised or disposable hosting sites, many of which are disguised as PDF files. The presence of embedded URLs and the nature of the link farm suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://laborke.ru/uplcv?utm_term=ip+address+android+device PDF link annotation
    • http://eastindiaspray.com/suvra/eastindia_spray/files/31100507613.pdfIn PDF document text
    • https://avukat.dnsaktif.net/upload/files/jufabamuvuk.pdfIn PDF document text
    • https://kingcarmotorista.net/uploads/files/dabufaba.pdfIn PDF document text
    • https://ekinyalitim.com/depo/sayfaresim/file/viwafularafofi.pdfIn PDF document text
    • http://tvcsoltau.de/userfiles/file/gonalabamarupatumosila.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f731d490db---11892608281.pdfIn PDF document text
    • https://bbox.ru/images/shared/file/11734605469.pdfIn PDF document text
    • http://theemasternetworker.com/ckfinder/userfiles/files/woraxivabuwerif.pdfIn PDF document text
    • https://adtw1.elfjane.com/ckfinder/userfiles/files/79796352300.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612fac533813f---neputujojezik.pdfIn PDF document text
    • http://ecme.site/2015/vat/upload/files/38701167476.pdfIn PDF document text
    • http://olech-rzeszow.pl/userfiles/file/27625415895.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/7s3se8pr7dueekkt1l5d1g8grv/fefaladewovog.pdfIn PDF document text
    • http://www.fdconsult.qa/public/uploads/cms_files/44768393536.pdfIn PDF document text
    • http://trustycctv.com/ckfinder/userfiles/files/jeposodidipiwexifuvejoxag.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133b1f741f39---88185590927.pdfIn PDF document text
    • http://nrgmedia.hu/files/file/jodenukun.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16138ada1c00ac---67209125463.pdfIn PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/renitobowinububizolurite.pdfIn PDF document text
    • http://kibbkw.com/uploads/file/83501768805.pdfIn PDF document text
    • http://myucpb.net/userfiles/file/57730089697.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/vopexunezax.pdfIn PDF document text
    • http://bluebirdcanada.com/FileData/ckfinder/files/20210911_0E593FCFBA88DDE7.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/9g3cv9m4lfp37uludchmr952q0/42548829116.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://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_off0000dafd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAFD 10380 bytes
SHA-256: 653389c71bd0c030f08a5add0b559df0d6918118f171b15139bf1efe2a6bc7b0
font_01_sfnt_off0000f294.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF294 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010aa6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AA6 17856 bytes
SHA-256: 7ae58d6f2ec6a7c1f2c0fcb431f269d294c96e54e7f0274d581fd90621079784