Malicious PDF — malware analysis report

Static analysis result for SHA-256 409c51b3cb25aa22…

MALICIOUS

PDF

79.7 KB Created: 2021-08-12 21:28:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: da451af28a138ff7a55dfac6dfc3880c SHA-1: 72274caf6246586d5857191c76c1da274a857918 SHA-256: 409c51b3cb25aa223c0c28617926b7ba9f6a3d9053003aac74dfd7a8df14a1e6
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and a link farm pointing to multiple distinct hosts, suggesting it's designed to redirect users to potentially compromised sites. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating the use of disposable or compromised hosting for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/tromo9egd8jvcdn287ai1tqv43/wavowopuwadofesove.pdf In PDF document text
    • http://alarcon-v.com/editor_upload_image/file/guxemo.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f10b600d747---logafupalojunazev.pdfIn PDF document text
    • http://takemehometomatoes.com/ckfinder/userfiles/files/25044965015.pdfIn PDF document text
    • http://studio-castiglioni.com/userfiles/files/fomagabatukefejamesufa.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/ccebb01fa677f9286d78f466daa1e9d3/89803217171.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1a31d7b96c---20507384400.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/410ed57fa6eea37f3b74bd75952b5135/sagibapepelag.pdfIn PDF document text
    • http://finchamauto.com/pics/36677710684.pdfIn PDF document text
    • http://linpus.com/app/webroot/userfiles/files/pinuwevup.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/93615434220.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/65969187543.pdfIn PDF document text
    • http://phuclocvienjsc.com/uploads/image/files/71288966884.pdfIn PDF document text
    • https://kuzeyilac.com/resimler/files/nikugezirelimirebe.pdfIn PDF document text
    • http://grandrosso.com/js/upload/files/14473058595.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/15l0kcgkuq5at7fp1n8b2gat7n/217196333.pdfIn PDF document text
    • http://minhvuongthuphap.com/upload/ck/files/xesazawirotudimokepis.pdfIn PDF document text
    • http://stepasidemedical.com/images/uploads/file/94992389720.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7a9b79f7e---xukifo.pdfIn PDF document text
    • https://szallas-karpatalja.net/upload/66443833773.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/wuzezafatusifumaxudodaze.pdfIn PDF document text
    • http://ural-resyrs.ru/data/file/lizozowegolafurone.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e5341c16fe---55197823432.pdfIn PDF document text
    • https://eksiliotomotiv.com/upload/ckfinder/files/tamuwuvami.pdfIn PDF document text
    • http://omak1968.com/clients/71178/File/fowekunilapew.pdfIn PDF document text
    • http://busangh.com/attfile/fckimg/file///20210731211432_1025688164.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/a8b9bd7bd2d03875f00a436b2fd03e39/97815900018.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=minecraft+pe+0.14+0+aptoidePDF 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://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_off0000cb67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB67 21164 bytes
SHA-256: b22435650dacdc3b142054b144856764ab8e655b48090cfda61a59b88bc57b81
font_01_sfnt_off0000ff91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF91 10712 bytes
SHA-256: a5054328255b56823e2833ef295ba289836d4dd57d7fdae7c6cb90b10ee4f836
font_02_sfnt_off00011852.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11852 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1