Malicious PDF — malware analysis report

Static analysis result for SHA-256 a228121d783d8855…

MALICIOUS

PDF

76.8 KB Created: 2021-09-15 22:14:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: de4edd41439c288fd5d6903f6897cd38 SHA-1: 1f24cf8e509363dc42a575b53c9e676baa04bb46 SHA-256: a228121d783d8855832f5fb3c4662d216c64dfa618c16bf98aba856933fb8080
134 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to redirect the user to one of the malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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
  • 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 https://allytemp.ru/uplcv?utm_term=office+365+student+email PDF link annotation
    • http://industrialsupplies.pk/userfiles/files/76828605383.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/robodilafemiwaxira.pdfIn PDF document text
    • https://gastriklandsbf.se/UserFiles/files/36950433882.pdfIn PDF document text
    • http://amsuatrust.org/survey/userfiles/files/54920647200.pdfIn PDF document text
    • http://ombs.ru/uploads/files/40289449759.pdfIn PDF document text
    • https://www.theoakshealthcare.com/my_content/js/ckfinder/userfiles/files/dirarovugijuzejurur.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/41773124014.pdfIn PDF document text
    • http://gr-chem.com/upload/files/55318992225.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/8266155877.pdfIn PDF document text
    • https://jungleflightchiangmai.jungle-flight.com/Uploads/files/48006137222.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f01dd6acab---sagifi.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/7b1f2c2fd616cde5718c5d24402cc785/4852324761.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/26590053219.pdfIn PDF document text
    • http://ceroki.com/image/files/72190616959.pdfIn PDF document text
    • http://bouwbedrijfansing.nl/userfiles/file/36712731737.pdfIn PDF document text
    • http://hanauhrova.cz/files/79603645316.pdfIn PDF document text
    • http://travelcenterpuntos.com/campannas/file/lekawifokefow.pdfIn PDF document text
    • https://mangonebike.com/uploads/file/705789788.pdfIn PDF document text
    • http://kaztelcom.kz/ckfinder/userfiles/files/vexudajifesanaja.pdfIn PDF document text
    • https://signatureshreyas.in/userfiles/file/senubonibifegasisubipu.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/nukoboxigibob.pdfIn PDF document text
    • https://www.leadercaravans.com.au/application/third_party/ckfinder/userfiles/files/lelunotasa.pdfIn PDF document text
    • http://chaukitchen.com/uploads/files/fonokokonajuju.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_off0000c994.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC994 16540 bytes
SHA-256: 72d3208f06bd1616e16b30d0ba58de3aa968422bc610508bd0dc5abc1471ee01
font_01_sfnt_off0000f444.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF444 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C5B 11016 bytes
SHA-256: a1f7b6bf8baa28e6d77e947c08582cb5fb8a64705883ecd605852b0357554e78