Malicious PDF — malware analysis report

Static analysis result for SHA-256 536af61f53d406d7…

MALICIOUS

PDF

71.3 KB Created: 2021-09-28 11:56:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ed3c5920e5240368d1a172aa94cf67c9 SHA-1: a01dcb21850cc6631eb52b9467c6fd6832b16183 SHA-256: 536af61f53d406d748d72f0db0df9803086311218e22e0cebe24297f5861adc7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and ML classifiers, indicating malicious intent. It contains numerous external links, many pointing to potentially disposable domains, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to redirect users to malicious sites, likely as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://jamesandsons.ca/userfiles/file/9603551541.pdf
    • http://fetogram.com/images/upload/files/sezim.pdf
    • https://ubk-sad.de/azubi/userfiles/files/79075662041.pdf
    • http://wskinbody.com/data/boardData/files/1350056404.pdf
    • http://k3projekt.pl/uploads/userfiles/files/judavutodagofujufozexemu.pdf
    • http://hftyby.com/upload_fck/file/2021-9-1/20210901110834515231.pdf
    • https://interstudy.net/userfiles/file/1282188654.pdf
    • http://aibasylhet.edu.bd/app/webroot/ckfinder/userfiles/files/90627585449.pdf
    • http://c2ctrading.org/cms_upload/files/61103972150.pdf
    • https://safe-international.com/userfiles/file/32079628207.pdf
    • http://3gr-group-com.gbintl.com/ci/userfiles/files/sunaxisevoloponowodeloxo.pdf
    • http://pvvc.cz/files/2117161507.pdf
    • http://erodiertechnik-wenzel.de/userfiles/file/zitegemanesuveniman.pdf
    • https://rosedreamholidayhomes.com/ckfinder/userfiles/files/koporabuzuvepebowu.pdf
    • https://rafaellopezehijo.com/upload/files/1850724762.pdf
    • https://alzubidi.com/userfiles/files/nepaz.pdf
    • http://celcg.pl/uploaded/file/lapibozijopajudibat.pdf
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613d11194cf29---kirebixa.pdf
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/690abc9df2528e03f220996c17f2b064/mevuxamiratunopufujeva.pdf
    • http://bnblspecialities.com/userfiles/files/magiwizojerogipotunutumix.pdf
    • https://dom4m.lv/userfiles/files/ramofanodef.pdf
    • http://www.s4b.nl/upload/files/puvevepog.pdf
    • http://express-service-auto.fr/ckeditor/ckfinder/userfiles/files/85684758475.pdf
    • http://www.hon-ro.hu/userfiles/files/ximovovitod.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+organize+photos+on+android
    • 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_off0000b365.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB365 16792 bytes
font_01_sfnt_off0000cb7c.bin
568f2a01763d497fdccbcb96f14f6976e7f418eed5e27c7d4adf1c8cf40c45b6
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB7C 10760 bytes
font_02_sfnt_off0000e403.bin
f4030073f5d653cba872a204a651bf7b17ac496819399385f76144cf444277c0
pdf-font-stream PDF embedded font (sfnt) at offset 0xE403 17112 bytes