Malicious PDF — malware analysis report

Static analysis result for SHA-256 f7b23ac215f8e505…

MALICIOUS

PDF

76.3 KB Created: 2021-09-03 19:22:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: ed16e1d80768db3115ee9c3701e8a92c SHA-1: 1d9ff7fffff3118dfcd33c7bc78028605acc4b2b SHA-256: f7b23ac215f8e505be24b6e45c1f1a2305ce5f53e11fca5a6824cdcf1fdfda2a
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The embedded URLs are likely used to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://2446665a.ru/ckfinder/userfiles/files/loxakulidotifo.pdf In PDF document text
    • http://brickform.cz/obrazky/files/voxidoxutes.pdfIn PDF document text
    • https://amadesafar.ir/basefile/amadesafarir/files/bakufegolamodid.pdfIn PDF document text
    • http://risme.vn/files/tawirejuz.pdfIn PDF document text
    • https://tonthephunglan.vn/upload/files/32977502234.pdfIn PDF document text
    • http://nbkhjc.com/uploads/202107/file/210725002545916267wba35z6o12k4.pdfIn PDF document text
    • http://www.pilonidalsinus.gen.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607060a3c0f44---juropubenu.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a16865ec2be---76191636205.pdfIn PDF document text
    • http://webursitet.org/Files/file/22006250871.pdfIn PDF document text
    • http://anupbolivia.com/images/files/mipajapoxeselesiwij.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/9b522ca291c85bd72b53129983b80db8/gesuvasamojisanomekizuber.pdfIn PDF document text
    • http://jtravel.clickis.kr/FileData/ckfinder/files/20210830_800D57B74CB19DC7.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/kmp0en7bt2na93dkmeuho08bvl/rujulobutatanesitavokuzi.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a21f34a4c04---laxokuwexovulo.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1610dc15880401---kadalaziloxus.pdfIn PDF document text
    • https://mobile-translator.eu/app/webroot/media/files/54688433278.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e9c3ea4359---8063484984.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/b5d85e17f4078df8311fe09d678a0b04/pinidiwazikunuzogovolekal.pdfIn PDF document text
    • https://dynasty888.com/image/files/20210531_223330.pdfIn PDF document text
    • http://hwayinn.com/image/files/20210819_195932.pdfIn PDF document text
    • http://ivepe-elearning.gr/assets/UserFiles/mainHome/file/guzas.pdfIn PDF document text
    • http://rlmlaw.com/images/edit_images/file/levebabewozikiwawiluri.pdfIn PDF document text
    • http://reanda.com/jingkelun/userfiles/files/20210725125713.pdfIn PDF document text
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16083c7f273f5b---jirevunanetolakuxuset.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=free+english+worksheets+for+1st+gradePDF 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_off0000c754.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC754 10840 bytes
SHA-256: cff752732453da326a76a708167842235629c02e8669c9dc920c02c6d69391f1
font_01_sfnt_off0000e02c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE02C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f83e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF83E 16588 bytes
SHA-256: 5865f3911d189ff92bce2ebe5197381144a693ffd4e29e7795f3e6ce35457b97