Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a53f82cabd18808…

MALICIOUS

PDF

75.9 KB Created: 2021-09-13 07:37:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ef02a83c91698de5968ff4391703c494 SHA-1: 4afb733c15934c84baad16816ad96a58cbc3bed6 SHA-256: 5a53f82cabd1880898f1be86314db988abe67818893c4a85bc9d7e6534c9e186
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using numerous links on different hosts, often with UTM parameters, to potentially improve search engine ranking for malicious content or to distribute phishing lures. The presence of compromised CMS upload links further suggests an attempt to host malicious content on seemingly legitimate but compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://philabc.ru/uplcv?utm_term=facebook+page+manager+app+apk PDF link annotation
    • http://denkobarbell.com/_upload/files/91629394384.pdfIn PDF document text
    • http://megatex-plast.ru/pub/file/19722129719.pdfIn PDF document text
    • https://cecprint.com/images/file/litemavabopuwafutawokuj.pdfIn PDF document text
    • http://gediklimakinahidrolik.com/resimler/files/60743846432.pdfIn PDF document text
    • http://tce.vn/imagesflashupload/file/17656485144.pdfIn PDF document text
    • http://tuclubcr.com/campannas/file/ralip.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/411a0eaabebef89fe57b8d518d0e8886/fagefinimopakaluwofode.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/77583323337.pdfIn PDF document text
    • http://kkc1.org/htdocs/cljr/data/files/74702124460.pdfIn PDF document text
    • http://www.contal-farmer.com/uploads/files/77269338164.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/161300431cfeb1---22770789352.pdfIn PDF document text
    • http://synergienetwork.net/userfiles/file/latepivogunumafolesun.pdfIn PDF document text
    • http://zbigniewrodak.pl/galeria/file/wolakuzafodojejojadova.pdfIn PDF document text
    • http://lachina.cn/upload/file/43803653228.pdfIn PDF document text
    • http://tobn56.com/UpFiles/file/18861820922.pdfIn PDF document text
    • http://kfnmsz.com/upfolder/e/files/20210902170555.pdfIn PDF document text
    • http://aroma-es.red/yamituki-n/uploads/files/39738460660.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16139ee19419ab---gepakazugitut.pdfIn PDF document text
    • http://hart-metale.pl/gimnazjum/userfiles/file/jotatiwituxijawuvil.pdfIn PDF document text
    • http://yenidenyuzlendirme.com/ckfinder/userfiles/files/fojobumevugefebupofa.pdfIn PDF document text
    • http://woodlandhills.ilovepokebar.com/uploads/files/56678332613.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_off0000c038.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC038 19236 bytes
SHA-256: 2ebc58db1281eed25a9dd628967dcade4ae0dfc6524051e2c64a3e5a5f3f9e0a
font_01_sfnt_off0000f268.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF268 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010a7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A7F 10524 bytes
SHA-256: b8b0e2b9b22556c89854176ee79c9917703a76ad0a63926cd244323c7d8d26cb