Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1f403c22c168e7f…

MALICIOUS

PDF

70.7 KB Created: 2021-10-02 15:25:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 127417ce6f78f174802230a62db7e7f9 SHA-1: b2077225a73be3e2b2e671e6ef364fa780ee9b24 SHA-256: a1f403c22c168e7f607775d0930f1509fa5e3b591756e75cf2d8ccbdf734302e
156 Risk Score

Malware Insights

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

The PDF document exhibits characteristics of a link farm, with numerous embedded URLs pointing to other PDF files hosted on potentially compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO poisoning to distribute further malware. No scripts were extracted, and the document body was unreadable, so the rationale is based on the URL heuristics and AV detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9893

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://pistant.ru/uplcv?utm_term=3+in+periodic+table PDF link annotation
    • http://ncfc.com.tr/ckfinder/userfiles/files/53463819894.pdfIn PDF document text
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/33818924282.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/39bcd648b7ebf756f502f19f39d8e111/62422866743.pdfIn PDF document text
    • http://scuderieverdina.it/scuderia/userfiles/file/22092089075.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/84875162041.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139842ae4afb---tajofaximosubav.pdfIn PDF document text
    • https://buildingexpertsdirectory.com/ckfinder/userfiles/files/gajerix.pdfIn PDF document text
    • http://xn--80adic7alej3d.xn--p1ai/userfiles/file/feremonenase.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///71550538970.pdfIn PDF document text
    • https://maryamghiasi.com/images/upload/files/nubadegeripapitigu.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/b72938c30fd5e0e53ee52c3e8c5aeb5b/dexite.pdfIn PDF document text
    • http://bugskin.org/userfiles/file/69605925284.pdfIn PDF document text
    • http://abnicum.ru/files/file/zabegamanuxepi.pdfIn PDF document text
    • http://yesfabric.com/images/upload/File/tozetuzejepidere.pdfIn PDF document text
    • https://cgeminfos.ma/upload/file/gogono.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/pusibi.pdfIn PDF document text
    • http://clinton.abwingsmd.com/uploads/files/77329044251.pdfIn PDF document text
    • http://studioassociatoemc.com/userfiles/files/tixefiparudoruwuwefuzeda.pdfIn PDF document text
    • http://geasit.it/userfiles/files/35328754500.pdfIn PDF document text
    • http://pegastelco.com/pictures/files/54299376574.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/52974057934.pdfIn PDF document text
    • http://www.depomatrial.com/file/raxuxulakibijek.pdfIn PDF document text
    • http://etkindenetim.com/resimler/files/37961659567.pdfIn PDF document text
    • http://mitchelllawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rezokesinavuwim.pdfIn PDF document text
    • http://mintaialuminum.com/d/files/juwatotadipuxiwuf.pdfIn PDF document text
    • http://www.civilhospitalpalampur.in/img/uploads/files/17175342041.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_off0000b2a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2A5 10552 bytes
SHA-256: e7cda8d2f218651fd2b4e73a96fe82b71b27e85ec0401c5419577aa4498d8357
font_01_sfnt_off0000ca7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA7A 16720 bytes
SHA-256: e708b831a2425ff98a052b1571199c6e60ea3b4d62c5f40cf5c60c020ac8e44b
font_02_sfnt_off0000f53d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1