Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc403cd5da0f39bc…

MALICIOUS

PDF

73.7 KB Created: 2021-09-19 18:13:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8b96caa6daf64b9e84ab2b9f3931b00c SHA-1: da102d65afe6c9f2d8f383cbb89ae045e5b2eea8 SHA-256: dc403cd5da0f39bccb0448eb98e0ac3486e98feae73cb84cb009ad14e99d10b0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple disposable hosts, a common tactic for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing unwanted software. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://drafthe.ru/uplcv?utm_term=live+net+tv+4.7+apk+download+for+android
    • http://xn--9w3b270a7kf.kr/ckfinder/userfiles/files/lepupisudejusoxer.pdf
    • http://hoclaixebinhthuan.com/upload/contentFile/file/kosudezamurutuwe.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16141389650a02---bigajipevufefilizavemomos.pdf
    • http://emilybarnes.com/DEVELOPMENT/VERSIONED/emilybarnes/trunk/sites/default/files/file/timilolur.pdf
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/161451bda421d4---19289046834.pdf
    • http://networkinglikepro.com/ckfinder/userfiles/files/69609081365.pdf
    • https://www.oalysa.cz/ckfinder/userfiles/files/26790430123.pdf
    • https://dtd.com.pk/ckfinder/userfiles/files/xisafixabawagorawixo.pdf
    • http://drkoopman.nl/cmsimages/file/xekenibekipakedomilu.pdf
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/161457d00e0256---11534952089.pdf
    • https://holocaustresearch.pl/nowy/photo/file/takafuninijisejawi.pdf
    • https://netcsemege.elelmiszer-hazhozszallitas.hu/ckfinder/userfiles/files/51431903855.pdf
    • http://amandatravel.com/userfiles/file/31951730770.pdf
    • http://www.ferm-matic.fr/upload/file/lororijodiwefaxasaxa.pdf
    • https://uleiuri.ro/userfiles/file/84721291331.pdf
    • https://anbuadidravidarmatrimony.com/ckfinder/userfiles/files/tetipiduvivasosedat.pdf
    • http://heathrowairporttaxi.website/userfiles/file/rosepinatum.pdf
    • http://drivescuolaguida.it/userfiles/files/lunuwelisofilugawevowo.pdf
    • http://fertilityupdates.com/userfiles/files/bigedagagerege.pdf
    • http://www.lukoilmarine.com/ckfinder/userfiles/files/54461968046.pdf
    • https://y3stwk65l-mn9.com/contents/files/ratemojiniro.pdf
    • https://securitydm.rs/slicice/file/53887184190.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_off0000bae3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBAE3 16792 bytes
font_01_sfnt_off0000d2f5.bin
0adabb062598a1724c287eef0858e709dc42a2cd99b02d1c3200502255394f43
pdf-font-stream PDF embedded font (sfnt) at offset 0xD2F5 17380 bytes
font_02_sfnt_off0001003d.bin
b8ddbf7f8d3d1cd9b87fac3d59b695c917869e21fb67885c3527f0c36db5bdb9
pdf-font-stream PDF embedded font (sfnt) at offset 0x1003D 10720 bytes