Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7538fe5c3e91fea…

MALICIOUS

PDF

67.7 KB Created: 2021-10-02 11:57:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bf7bf6966d9a9451bd1e66f815857523 SHA-1: 65a65c35417caa3146a6ead7d2c1eaf7e67a9ea2 SHA-256: a7538fe5c3e91feab181487b5720c1c74292b89555717577c1b28ab8d9822615
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://smidgel.ru/uplcv?utm_term=formative+assessment+in+maths
    • https://agencement-menuiserie-var.fr/stockages/files/95954667193.pdf
    • http://podiummoda.ru/userfiles/file/34146512419.pdf
    • https://casasholidays.com/scgtest/team-explore/uploads/files/54389953209.pdf
    • https://nsck-cykelmotion.dk/ckfinder/userfiles/files/jeminedumu.pdf
    • http://fazendasaojudastadeu.net/fotosempresa/files/55200141210.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/cbe6553442afc7d4b863f20b1bd83088/xidokemugodejal.pdf
    • https://pima-alarms.net/slicice/file/jirujovoji.pdf
    • http://margheritango.it/userfiles/file/sepezukuzipimeka.pdf
    • https://study-abroad-travel.com/ckfinder/userfiles/file/3570543947.pdf
    • https://tckontrola.hr/files/91964915227.pdf
    • http://pasted-radio.de/web/files/zemamajunimarilisuxelum.pdf
    • http://dongzzang.com/userfiles/file///puzivulosukipukanetinu.pdf
    • http://24x7taazasamachar.com/assets/ckfinder/core/connector/php/uploads/files/49505629301.pdf
    • http://mfahk.com/upload/files/61528916788.pdf
    • https://pecintajp.com/contents/files/kejut.pdf
    • http://sun-green.be/ckfinder/userfiles/files/malogebufeposuzavol.pdf
    • http://unityproductions.com/upload/files/61784999301.pdf
    • https://lodoshosting.com/calisma2/files/uploads/64348758261.pdf
    • http://metzgerei-bischof.de/userfiles/file/juzovopo.pdf
    • https://advik.net/userfiles/file/82341420608.pdf
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16133e9cb0f98e---wonumopavaxeniwisefidos.pdf
    • http://kovovyroba-nosniky.cz/UserFiles/File/vixitunaxemisubagolefasu.pdf
    • https://isosklo.cz/uploads/xefegidowipi.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16143ebbfc6271---3606315023.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000aedd.bin
97a8692cbe72e189d1ff4eef3a71b9baf8458056db99bbee21a41bc5eeeec9ac
pdf-font-stream PDF embedded font (sfnt) at offset 0xAEDD 10372 bytes
font_01_sfnt_off0000c61e.bin
b9318fb496d345f48a3032c8a842523fb4d94a9065b3fae97bfa6a14cc1c82fb
pdf-font-stream PDF embedded font (sfnt) at offset 0xC61E 14292 bytes
font_02_sfnt_off0000e95e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE95E 16792 bytes