Malicious PDF — malware analysis report

Static analysis result for SHA-256 76183c832cfb46d9…

MALICIOUS

PDF

74.8 KB Created: 2021-09-09 18:07:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 44b9a9bfde16c114266347546327f389 SHA-1: d2cdd9446b97fe7f00453958af066d0b6eda6ab1 SHA-256: 76183c832cfb46d9fff6648c0fc00dd23312617f25431c1eec06710f53be2d25
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to phish users or lead them to malicious content. The presence of multiple external URIs and a link farm heuristic strongly indicates an attempt to redirect the user to a secondary malicious resource.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://rvhifi.cz/files/file/wuxevasiwukiviwifuzu.pdf In PDF document text
    • http://smirna.pl/files/file/migulunopozejifalibudeb.pdfIn PDF document text
    • https://pergamine.com/ckfinder/userfiles/files/kavaxosudekoronepusawiz.pdfIn PDF document text
    • https://10fci.org/userfiles/file/98754994185.pdfIn PDF document text
    • https://lapakunited.com/contents/files/dojuwinepizenogu.pdfIn PDF document text
    • http://dreamcatcherltd.com/userfiles/file/86406816332.pdfIn PDF document text
    • http://futureinfashion.com/ckfinder/userfiles/files/fonojixup.pdfIn PDF document text
    • http://strap.sk/uploads/files/nebek.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/e9b25cc6319a4edf253b1ff2b583199a/xovarawokidimuzajam.pdfIn PDF document text
    • https://fallsplat.se/bildbank/file/tolarewateluvuwo.pdfIn PDF document text
    • https://gelblighting.com/userfiles/files/51275898973.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161326f0621d89---95457493799.pdfIn PDF document text
    • https://newegys.egyseg.eu/ckfinder/userfiles/files/1150821438.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613457e5ecb67---84051346049.pdfIn PDF document text
    • http://olivetheater.com/userData/board/file/44870303539.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/piwodona.pdfIn PDF document text
    • https://esvigo.com/upload/files/72327125266.pdfIn PDF document text
    • http://gz-chengeng.com/uploadfile/files/34156478327.pdfIn PDF document text
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/48192059752.pdfIn PDF document text
    • http://linpus.com/app/webroot/userfiles/files/xikuf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=fire+resistance+armor+minecraftPDF link annotation
    • 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_off0000ba84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d296.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD296 19648 bytes
SHA-256: b3dc609e024f7762fd6336aae3020a71d36c990cdac1bc1712b00e9942ebe8cd
font_02_sfnt_off0001066a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1066A 10428 bytes
SHA-256: 299a8e74cc758a2ea3c512b5bcdc7b028073be747e95677f627daa7bfb84c4d9