Malicious PDF — malware analysis report

Static analysis result for SHA-256 e7d39ac7e736786f…

MALICIOUS

PDF

81.3 KB Created: 2021-09-21 09:53:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 16cbdbd95a241356b33bb1645598aaed SHA-1: bb58a463b16fd7ee89460b0cbb8823a1019a224c SHA-256: e7d39ac7e736786fbe2bda12554fc5dc0e9f84d0cd3d161b8d05f39b037eb59d
104 Risk Score

Malware Insights

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

The PDF contains numerous links to disposable hosting sites, many of which are disguised as file downloads. The presence of a visual download button lure further supports the malicious intent. The ML classifier also strongly indicated maliciousness, suggesting the document is designed to trick users into downloading malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://synerhu.ru/uplcv?utm_term=vpn+master+apk+pro PDF link annotation
    • https://deltagroup.bg/uploads/file/24247975020.pdfIn PDF document text
    • http://xn--h49al71atridzo.com/userData/board/file/tolarigurusikerizewurut.pdfIn PDF document text
    • http://xn--b1akwe.xn--p1ai/userfiles/file/jawetigi.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/42ei2198jmob2himj7n0vr18of/fezorowifizelokuf.pdfIn PDF document text
    • http://domesticsolutionsagency.com/userfiles/file/53992523065.pdfIn PDF document text
    • https://rumusjitu.com/contents/files/safoneratunodimolakusi.pdfIn PDF document text
    • https://frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/wavezuzukodiguxu.pdfIn PDF document text
    • http://fusen-es.info/yamituki-n/uploads/files/wuwaz.pdfIn PDF document text
    • http://hanstime.com/userData/board/file/59789770334.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cc1593ca6a---44326216662.pdfIn PDF document text
    • http://siripanyalamphun.com/user_img/files/10320700415.pdfIn PDF document text
    • http://www.kowel.com/ckfinder/userfiles/files/1630633916.pdfIn PDF document text
    • http://yves-segers.be/userfiles/files/70134447704.pdfIn PDF document text
    • http://daiichilogistics.com/uploads/news_file/25810342373.pdfIn PDF document text
    • https://ngaa.org.au/application/third_party/ckfinder/userfiles/files/sowigitopuwazikape.pdfIn PDF document text
    • https://dveropolis.ru/upload_picture/9155494642.pdfIn PDF document text
    • http://casaledellasignora.it/userfiles/files/52737059611.pdfIn PDF document text
    • http://banlinhkienlaptop.com/userfiles/file/monas.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/b5607e9b93e023b223982e6b9c42feef/24131146356.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/8f38bf4c449f322e3d8bd522f30ce348/virov.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_off0000da07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA07 10336 bytes
SHA-256: aa4c2b96adf8e943fa57641d7e179d11557258c0cfc3274c597734658119098e
font_01_sfnt_off0000f167.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF167 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010979.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10979 17788 bytes
SHA-256: 4fad1ad756f3bcde95850f87526a7f94e71bc522ab6aa365d05289e6341dcb67