Malicious PDF — malware analysis report

Static analysis result for SHA-256 86bc6313ebab48e5…

MALICIOUS

PDF

72.1 KB Created: 2021-05-07 06:52:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: f54c0832062f0ff517083e784bf98d7b SHA-1: 40e6bd41d5c3261125a8edbbdb4d3be6df5e61dd SHA-256: 86bc6313ebab48e5a54e459edbae69930ba2b617f32361877d486d54aaf69b8f
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites used for hosting PDF files. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to lure users to external sites, likely for phishing or malware distribution. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4d98c7151---66504553951.pdf In PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608118ba9c3dd---62345887035.pdfIn PDF document text
    • https://www.qlsny.com/wp-content/plugins/super-forms/uploads/php/files/ba9eeaba3703eac2917de37999666291/7978946105.pdfIn PDF document text
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/204c817c8d56c4505eb56866e3323658/fewed.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/6gdasciehan9c0fcmq8864v587/zurumobi.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608d4fe9193c4---gibuboxatada.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092eafd7670d---jolifofogeto.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/efc8ob2svfonha1go5cmh29js2/35444334249.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16082e20514a89---tifotiditeto.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f052f4ce8f---durevabunotonij.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/ka4vns0v19p6tc7l0pfrfdvvi2/bigusiguxotovolujamovazog.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16089d3164db96---jirakoguruf.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16080b8d2c79fd---77810854353.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076cf61c333e---nobidalorogasexopuzifisu.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/1cc1c809a4707c1bfcc5497f1b45e08b/kuwil.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=apa+format+citation+online+sourcePDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d13d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD13D 5032 bytes
SHA-256: ed712cc7a36566c1800510c055d7d44fce506d21fade8b997bfff02eeb8e42bc
font_01_sfnt_off0000e23c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE23C 10196 bytes
SHA-256: 2c8d4585e13c20a564cd6f572c7cef2837d849a7d852270d16424abdb88a80d2
font_02_sfnt_off0001051a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1051A 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333