Malicious PDF — malware analysis report

Static analysis result for SHA-256 35d54cfcdcf79fa9…

MALICIOUS

PDF

82.3 KB Created: 2021-08-18 09:29:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a691a5cce1cd99ba38fb3aa40702bcd7 SHA-1: dff413c4ad389f71d4052a0f06b430de00891c6f SHA-256: 35d54cfcdcf79fa959a14908a1231f4d406173d288d7a264c94d962a66e3b7e5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It functions as a link farm, containing numerous URLs pointing to various websites, many of which appear to be compromised or disposable hosting. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a deliberate effort to create a network of links for potentially malicious purposes. While no scripts were extracted, the structure and URL distribution suggest a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://catamma.ru/uplcv?utm_term=alaipayuthey+tamil+film+mp3+songs+free+download PDF link annotation
    • https://broodjedenbosch.nl/ckfinder/userfiles/files/povedizojudozagikojufi.pdfIn PDF document text
    • https://aspirecambodia-edu.org/userfiles/file/91280313090.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/mfq19v9c0ul9r0eq2opugvr3gj/48088102152.pdfIn PDF document text
    • http://tks-forever.com/upload/2021/07/03/file/57036363182.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/3f338ebb1be7766ad2f15b8b9edc32c3/karivesupetelo.pdfIn PDF document text
    • http://ruresept.ru/files/file/55034006308.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/tevikikuxozosagilufojewu.pdfIn PDF document text
    • http://snap-drone.com/userfiles/file/66030048121.pdfIn PDF document text
    • http://colegiosantarosa.com/uploads/imagem/file/jukogetukusitebefor.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/suxiditogoketumu.pdfIn PDF document text
    • http://dmscsmartlifeblog.com/userfiles/files/21888820393.pdfIn PDF document text
    • http://jyjjapan.jp/files/ckeditor/files/fajunagukuzebasidemivev.pdfIn PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/bj26u2g5imh1hh0f3hrcu8k2rh/75386527710.pdfIn PDF document text
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607ad0f4a0f54---36584973243.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d9ab2c6fe7---jitom.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/4e9c428cf0734277bef07ed933aac172/3430409010.pdfIn PDF document text
    • http://suseefinance.com/userfiles/file/sizazafob.pdfIn PDF document text
    • https://paron-rebondir.com/uploads/files/tufaxigo.pdfIn PDF document text
    • http://qiangka.com/ckfinder/userfiles/files/lawonuvakofibumibel.pdfIn PDF document text
    • https://soba05.org/wp-content/plugins/super-forms/uploads/php/files/9ced95343b697237722be752ff3a756f/jonob.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6034df361---38135355766.pdfIn PDF document text
    • http://kd-council.com/upfile/files/58379719077.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/308ef3e67d8ae053b752aa569db9641e/98347695572.pdfIn PDF document text
    • http://www.tramag.pl/upload/file/xebuv.pdfIn PDF document text
    • http://fullcolorspandoeken.nl/userfiles/file/rofeba.pdfIn PDF document text
    • http://valaptop.com/ImagesVA/file/seronumi.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_off0000dc9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC9E 16720 bytes
SHA-256: 4eeb6961d0fc62393cf6de6c0369311efb8bdaf643a6af36130efa50f1bebac2
font_01_sfnt_off00010839.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10839 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012050.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12050 11400 bytes
SHA-256: b5299b4d5b438a9485eed2ee36381ae3814a4c4a57b652935aac581cf3bdf744

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