Malicious PDF — malware analysis report

Static analysis result for SHA-256 5813998d691e94dd…

MALICIOUS

PDF

83.9 KB Created: 2021-09-08 22:12:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e9fd1bfebddd274ab282e39df4d94a0b SHA-1: 915a639c2e42db0296c5540633e3338a8db5b0af SHA-256: 5813998d691e94dd654e11ce17c7c30ce72a6679900999b864fa6d3486b2a3a6
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress upload directories or are hosted on disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The document body is heavily obfuscated and appears to be metadata rather than user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://wastran.ru/uplcv?utm_term=firestick+tv+games PDF link annotation
    • http://syntra.pl/userfiles/file/70869076391.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132e9deb3b12---gajofiwisapexeget.pdfIn PDF document text
    • http://xn--80aesyq.xn--p1acf/files/file/wiloratolepa.pdfIn PDF document text
    • http://crabandclaw.com/uploads/files/560911594.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/nnn0ql7d2akdbn9sq04apo3ndt/lolokenefipepuvolar.pdfIn PDF document text
    • http://lorichphoto.com/pictures/file/buraxekipuxob.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/aff7c6430c21e9198c85365a257eb014/1505641894.pdfIn PDF document text
    • https://srilangkapools.com/contents/files/viteminolupowomowiworaj.pdfIn PDF document text
    • http://www.insight-assessment.com/ckfinder/userfiles/files/tibajukasigogojiz.pdfIn PDF document text
    • http://www.pzkexie.com/up_files/file/29194997785.pdfIn PDF document text
    • http://sake-tori.com/images/library/File/96738602716.pdfIn PDF document text
    • http://swaving-stalinrichting.nl/ckfinder/userfiles/files/tizuwazuvodazadojosuduni.pdfIn PDF document text
    • http://studiogallerani.it/userfiles/files/kafotifixuzasuvedu.pdfIn PDF document text
    • http://gzmingjun.com/uploadfile/files/20210907_134429.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/sugugesijaruvapum.pdfIn PDF document text
    • http://promocode.lu/userfiles/files/49027995096.pdfIn PDF document text
    • http://55pluscommunityspecialist.com/userfiles/files/18151745078.pdfIn PDF document text
    • https://matratva.in/userfiles/file/wudovuxosazojid.pdfIn PDF document text
    • https://agroadvanced.com/app/webroot/newsletters/editor/files/23510697639.pdfIn PDF document text
    • http://maurovalleferroarchitetto.eu/userfiles/files/58036407958.pdfIn PDF document text
    • https://aradovan.com/userfiles/file/xogakebata.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/161318ca458ea7---51298472239.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_off0000e114.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE114 10440 bytes
SHA-256: 65f869f3bbe34c76081433b50b28795c95019cfcb2b1bad8c64c387fd35e5eb3
font_01_sfnt_off0000f8d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D9 18852 bytes
SHA-256: 7b10a2d7d50fb7c46d551b1f7d47fd11239c0cf6d5a662dfd7cd342551810064
font_02_sfnt_off000129fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1