Malicious PDF — malware analysis report

Static analysis result for SHA-256 a83a41f9649236e9…

MALICIOUS

PDF

69.6 KB Created: 2021-09-14 03:43:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 2a932dfcab7f32a1fbe29d8dcbf9a16e SHA-1: e6f248c4d33ee6f510d5a85fbd6c246ab25e7edd SHA-256: a83a41f9649236e9c02a8289f9a742669ad8a6f151a9b7ff19a32326e42d924d
126 Risk Score

Malware Insights

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

The sample was flagged by a machine learning classifier and ClamAV as malicious. It contains numerous embedded URLs, many pointing to domains that appear to be part of a link farm, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The primary purpose seems to be directing users to external, potentially untrusted, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://get-insurance.in/ckfinder/userfiles/files/tumozowubudevudivexawem.pdf In PDF document text
    • http://bn-biz.com/userData/board/file/misivudelifunoxiwebos.pdfIn PDF document text
    • http://shopphutungmayphat.com/upload/img/files/5493084671.pdfIn PDF document text
    • http://the100voicesofgospel.de/fichiers/newsletter/file/2381134042.pdfIn PDF document text
    • http://accapierre.it/userfiles/files/11039315885.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/2397918247.pdfIn PDF document text
    • http://jungam21.com/upfiles/file/1631135179.pdfIn PDF document text
    • http://firewaterdamagedfw.com/test/fckeditor/uploadfiles/file/83500761058.pdfIn PDF document text
    • http://bolt.fo/public_html/userfiles/files/minoluduselemowo.pdfIn PDF document text
    • http://vako.vn/app/webroot/uploads/files/sinazonu.pdfIn PDF document text
    • http://hostingureitings.lv/uploads/userfiles/files/25763518688.pdfIn PDF document text
    • http://unitec-egypt.net/userfiles/file/22299159446.pdfIn PDF document text
    • http://edukoc.net/userData/ebizro_board/file/40491611012.pdfIn PDF document text
    • http://sochisushi.nl/survey/userfiles/files/pojubefodajame.pdfIn PDF document text
    • http://jmvlpslimited.com/ci/userfiles/files/puwibukawaxevizolamisoxuj.pdfIn PDF document text
    • http://ketoanantamhcm.com/uploads/files/fetoxewomolunekof.pdfIn PDF document text
    • http://drthchowdary.net/userfiles/file/90897746686.pdfIn PDF document text
    • https://canionglobal.com/FCKeditor/file/91131493091.pdfIn PDF document text
    • http://www.kevimotor-rock.hu/files/files/bemulaxudupadifunuwifo.pdfIn PDF document text
    • http://teedinmaesai.com/user_img/file/kirifuwuputoxuwupuviroxob.pdfIn PDF document text
    • http://milwaukee.center/userfiles/file/bufukitodusazatesepage.pdfIn PDF document text
    • http://mosvag.ru/img/lib/file/bujefabated.pdfIn PDF document text
    • https://27061010.com/uploads/files/202109100749127348.pdfIn PDF document text
    • http://yuha.be/_files/file/gujifamamanurokigorajenu.pdfIn PDF document text
    • http://fotocaroli.it/userfiles/files/noguwosexuzewarebajawumam.pdfIn PDF document text
    • http://homeopathyhongkong.org/files/pazaganuwula.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/gatanigikabu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=how+to+select+all+in+iphone+photosPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370b90efb54---26664585255.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_off0000b39c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB39C 10448 bytes
SHA-256: 4d9cd1a526f9d5aa67c4c4491eecf3228cdc832a46c8d82211c67c8262e0f6d2
font_01_sfnt_off0000cb47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e359.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE359 14744 bytes
SHA-256: 300743ff37e808152035dc7172c35d2ad619914acedb2e9668ce65e3bf814a7f