Malicious PDF — malware analysis report

Static analysis result for SHA-256 e55f94835fb30b35…

MALICIOUS

PDF

86.0 KB Created: 2021-09-13 04:46:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 16784bfbaed91994f18e113c0a9f242e SHA-1: 06bfc8e57d204d185691739789b33e3976c562ce SHA-256: e55f94835fb30b350e01cb20a4b6b93f9ffea6b4526272dde4c1fe4b990704ca
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple domains, many of which appear to be compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. The embedded URLs and the 'link farm' heuristic suggest an attempt to direct users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138e0ae6d726---3222452363.pdf In PDF document text
    • http://pibar.tw/uploads/files/202109051608069697.pdfIn PDF document text
    • http://ahjygjg.com/upload_fck/file/2021-9-6/20210906174328186507.pdfIn PDF document text
    • http://nirmalamathachurch.org/cms_uploads/image/file/nixuberuwekajabusipi.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8cf6ebe61---13399223519.pdfIn PDF document text
    • http://contua.org/userfiles/file/nirizig.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109102212214305.pdfIn PDF document text
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/44392264409.pdfIn PDF document text
    • http://reedxtrainternational.com/uploads/pages/file/31164171703.pdfIn PDF document text
    • http://mylodge-naoshima.com/susojife.pdfIn PDF document text
    • http://artikos.pl/userfiles/file/dovotujipopi.pdfIn PDF document text
    • http://xn----7sbicwad4afgcgd5aph7d5e.xn--p1ai/ckfinder/userfiles/files/66782056768.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/d75f31e7a0b8a5168256f2d4319acd3a/terew.pdfIn PDF document text
    • http://svx.su/ffile/file/luvekag.pdfIn PDF document text
    • http://poptheme.cn/uploadfile/files/20210906_164243.pdfIn PDF document text
    • http://pozitron-s.ru/userfiles/file/85475815956.pdfIn PDF document text
    • https://anitacalderon.com/ckfinder/userfiles/files/vomilebitono.pdfIn PDF document text
    • https://fultoys.com/userfiles/11467224034.pdfIn PDF document text
    • http://boki.hu/editor_up/74633592110.pdfIn PDF document text
    • https://fminterativa.net/cms/plugins/ckfinder/userfiles/files/dugukilagubixopu.pdfIn PDF document text
    • http://xedaptap.net/userfiles/file/38554821482.pdfIn PDF document text
    • http://kaizenlife.com/ckfinder/userfiles/files/tewakivuvojujemigig.pdfIn PDF document text
    • https://pragatitic.org/ckfinder/userfiles/files/nujeko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=why+am+i+getting+ads+on+my+android+phonePDF link annotation
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/57483839961.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_off0000eaf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAF7 17620 bytes
SHA-256: b85031123e2c71e9f384bbd697c3e8a854b83335874257abc023cec94199f08c
font_01_sfnt_off0001190e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1190E 10900 bytes
SHA-256: 171af1434de04d57053161533d537c55b977867a41da76751e628b7197280862
font_02_sfnt_off000131eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1