Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8c5646908b5a26c…

MALICIOUS

PDF

74.8 KB Created: 2021-09-08 10:04:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-18
MD5: 28a2caa4c4c167c7b54ad23ac973093b SHA-1: 88a5031163fd390fae9c7c949473cc1cba2b7a8d SHA-256: b8c5646908b5a26c5569026f4b59ca05e15b446d5ba33fa6e61816d59f92c8d5
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The file functions as a link farm, containing numerous URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The primary purpose seems to be directing users to external resources, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://medvor.ru/uplcv?utm_term=naim+unitiserve+manual PDF link annotation
    • http://szzxwx.com/Upload/Upload/file/20216142052557436.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607785793acd6---89833717646.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/859d3435895b8ef4e0c2d1c4806450c6/latutelaxojomedugafepi.pdfIn PDF document text
    • http://tourister.kr/userfiles/file/dujemiwomopifawozifoj.pdfIn PDF document text
    • http://sunnysolutions.it/uploads/assets/file/jomifibufavejejajake.pdfIn PDF document text
    • http://ty-int.com/files/files/vivubakefekililaselazijun.pdfIn PDF document text
    • http://datavincity.com/uploads/ckfinder/files/vedezovedakenipedomudoji.pdfIn PDF document text
    • http://goldmustang.com/files/files/6096532450.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/67f7f98a9f250987d03338e1ce973dd1/tipisenosubijiveruk.pdfIn PDF document text
    • http://cartopack.com/Images/file/xafusavadu.pdfIn PDF document text
    • http://betaempire.com/uploads/userfiles/file/file/75566513554.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/rijewagip.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f7d930d97f---26353614030.pdfIn PDF document text
    • http://dzwigipoznan.pl/userfiles/file/biboluvimijarutajagukop.pdfIn PDF document text
    • http://theettiaresmontreal.com/clients/f/f0/f03dfc1790708d0b03c48e9879ef2ea6/File/14212130604.pdfIn PDF document text
    • https://paeonia.ch/userfiles/files/rumopimi.pdfIn PDF document text
    • http://adriennemason.com/assets/files/92832367364.pdfIn PDF document text
    • http://laser-piskovani.cz/democms/userfiles/file/besebagiwemisubo.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/59464405979.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099e557bcc87---fofexebizubedatemuva.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f1584d40fdf---29303038230.pdfIn PDF document text
    • http://logo4you.dk/userfiles/file/vasaviroj.pdfIn PDF document text
    • http://etcad.net/np/upfile/file/76184910427.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_off0000c08a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC08A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d8a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8A1 10292 bytes
SHA-256: 06ed248f81669af6979d94ec44cd4752a04bea03f9872b03fb434b796be70f18
font_02_sfnt_off0000efc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC4 17120 bytes
SHA-256: cc7daa75efa7e8a091b84faf404f1af1324a56759939e2777303d702b8339b93