Malicious PDF — malware analysis report

Static analysis result for SHA-256 aaa66981cfdccd92…

MALICIOUS

PDF

74.5 KB Created: 2021-09-24 00:20:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d2e90dee742be83d09c0b5965f958355 SHA-1: 371bd5ac609aff17ae3ca371752197ee494fdba1 SHA-256: aaa66981cfdccd92dbba45140a88fb8566a291d112ed6e868dfa8542bbdac274
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious. It contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, suggesting an attempt to manipulate search engine results or distribute malicious content. The presence of 'utm_term' parameters in some URLs further supports the idea of tracking or directing users to specific lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://drafthe.ru/uplcv?utm_term=picsart+apk+download+pro PDF link annotation
    • http://vrieshorst.nl/images/uploads/file/11352723087.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/f9igichknj9scqpdtdkf3qarcf/15035442732.pdfIn PDF document text
    • http://zzlhlt.com/userfiles/file/LianMeng202109231907111923.pdfIn PDF document text
    • http://elskup.pl/images/assets/file/batedivimami.pdfIn PDF document text
    • http://dokumsuzgec.com/userfiles/files/tupetusazuwefegugudaged.pdfIn PDF document text
    • https://valkexclusief.reviewz.eu/app/webroot/files/userfiles/files/64340830568.pdfIn PDF document text
    • https://krzczonowice.pl/gfx/file/80869129985.pdfIn PDF document text
    • http://tlxzkj.com/uploads/file/050706419125.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/hn6hbri0bu3tjcsl46pum781ul/kesedavazuvaje.pdfIn PDF document text
    • https://marjoyunlar.com/calisma2/files/uploads/zujonizafuvijepodoruvi.pdfIn PDF document text
    • http://datong-travel.tw/upload/ckeditor/files/20210918194712.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/16146accf94d64---10544605485.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/33393144441.pdfIn PDF document text
    • http://apex-architect.ru/images/file/rizediv.pdfIn PDF document text
    • http://berallebags.com/UploadFiles/FCKeditor/20210915141147.pdfIn PDF document text
    • https://abss.pt/userfiles/file/puzutudagatukenonegob.pdfIn PDF document text
    • http://abwferrellpkwy.com/uploads/files/12797510555.pdfIn PDF document text
    • http://footstepfloor.com/upfiles/files/79564955108.pdfIn PDF document text
    • http://formel1vermietung.de/userfiles/file/86712071929.pdfIn PDF document text
    • http://geoass.eu/userfiles/files/xapum.pdfIn PDF document text
    • https://fibra-optica.ro/ckfinder/userfiles/files/91032081591.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/baroredujekoge.pdfIn PDF document text
    • http://gruaszarate.com/ckfinder/userfiles/files/65118062812.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_off0000c351.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC351 16052 bytes
SHA-256: 2853209679ba7eacf0074ea888beef2aa76ba27dc82434c5c78e47030eb72f98
font_01_sfnt_off0000ec4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010466.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10466 10556 bytes
SHA-256: 70ebe2f5bbea3137102fef5f416bd334d1e0c3d4b624d450ac3c440da0156ca3