Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e00939612f289db…

MALICIOUS

PDF

71.2 KB Created: 2021-09-13 22:57:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5465a8199abf3c2bbb88f4e7cb58a079 SHA-1: 450958eccbc8f7e7cfeecc592ae61ea3d7e1ba53 SHA-256: 8e00939612f289db187117258d0098086c4ccc0eb695709fa28ce51370e23a29
126 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, with one heuristic specifically flagging it as a link farm on disposable hosting. The PDF structure and embedded content suggest it's used to redirect users to a network of other PDF files, likely for SEO poisoning or to serve further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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.
  • 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://burmeseburmilla-allevamento.com/userfiles/files/musabodopagevoge.pdf In PDF document text
    • http://positiveforce.in/uploads/files/dogewabefujuli.pdfIn PDF document text
    • http://precisionsurgicalworks.com/alpha/ckfinder/userfiles/files/33418453361.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e766b9e1e4---fewipokejejoxukak.pdfIn PDF document text
    • https://kligi.viart.lt/ckfinder/userfiles/files/81854703253.pdfIn PDF document text
    • http://taiwanquinoafamily.com/shopadmin/upload/files/33437388420.pdfIn PDF document text
    • https://doanhnghiepvietnam.niengiamdoanhnghiep.vn/img_duhoc/files/13627186286.pdfIn PDF document text
    • http://chuabenhxuongkhop24h.com/images/files/tukifibox.pdfIn PDF document text
    • http://coumert.com/images/file/83728597220.pdfIn PDF document text
    • https://kakakmanis.com/contents/files/16460760417.pdfIn PDF document text
    • https://zhavezbozi.cz/data/file/gowelisalositipomunan.pdfIn PDF document text
    • https://trsoftyazilim.com/genelresimler/file/pukuvopipuzogefemewafazig.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/0b720a54b6f53940a486423b7489030b/82365356671.pdfIn PDF document text
    • https://12waktu.com/contents/files/jutedigilovo.pdfIn PDF document text
    • https://cargoservice.pl/cargoservice/userfiles/file/zubit.pdfIn PDF document text
    • https://gamma-electronics-eg.com/userfiles/files/bususumimuxisasedolazeg.pdfIn PDF document text
    • http://shriadinathbank.com/uploads/gikipowetal.pdfIn PDF document text
    • https://asiquim.com/ckfinder/userfiles/files/merakaxuwuwa.pdfIn PDF document text
    • https://btsmstlucia.com/atomicsteps/upload/userfiles/file/50702133308.pdfIn PDF document text
    • http://birkhoffhi.com/userfiles/files/zopivirokizimipukaf.pdfIn PDF document text
    • https://mraos.com/web/userfiles/file/14082819699.pdfIn PDF document text
    • http://xfswchem.com/upload/files/viluxatiwepane.pdfIn PDF document text
    • https://ksboutlet.com/file/files/posomivurulisijubix.pdfIn PDF document text
    • https://art4you.sk/editor_uploads/system/files/53063292806.pdfIn PDF document text
    • http://mlsy.cz/images/file/files/48449879867.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=world+map+latitude+and+longitude+pdfPDF 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_off0000b52f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB52F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD46 10764 bytes
SHA-256: 31e15c63bfb34c83d055decbb1ef65ab4bb55c9cfd6ec108fe5cf8dcf7dd31d9
font_02_sfnt_off0000e5c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C7 16140 bytes
SHA-256: b9bda2c5a5f483402c2bee592b9f05fb11d01281e6193b5b4eddf833e83792ed