Malicious PDF — malware analysis report

Static analysis result for SHA-256 31662c4efc5147c6…

MALICIOUS

PDF

72.1 KB Created: 2021-09-18 16:58:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9fc5c7743c4532b3c36bb2ec655ee503 SHA-1: a1bc47513aaf791dd4e539dfbb665ca02af775c6 SHA-256: 31662c4efc5147c6e5fb876e475894750dca55a870e729741e94fc69fb162692
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many hosted on compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content or phishing pages. The ML classifier strongly indicated maliciousness, and the presence of embedded URLs points towards an attempt to lead the user away from the document. No scripts were extracted, but the overall structure and URL distribution are indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://allytemp.ru/uplcv?utm_term=android+phonebook+app+source+code PDF link annotation
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16131d9be16dc5---28191532130.pdfIn PDF document text
    • https://profitaler.com/UserFiles/file/89873776271.pdfIn PDF document text
    • http://coffee33.ru/archive/file/jofasunatasobe.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/0a35988f8b7016df181aa308570635f4/finuxesabamumewo.pdfIn PDF document text
    • http://cableesmaltado.com/d/files/4946973652.pdfIn PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/5d68314ec1119afddfc819b617404276/73025886743.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/30155056806.pdfIn PDF document text
    • http://location-appartement-venise.com/italie_documents/files/20360510406.pdfIn PDF document text
    • http://speaklifeiamgreatness.com/files/files/20933470961.pdfIn PDF document text
    • http://constantcontinuity.com/membership/data/files/lugelomosow.pdfIn PDF document text
    • http://teknis.it/userfiles/files/xevutete.pdfIn PDF document text
    • https://nffcd.org/userfiles/files/xadabatugup.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/83374128613.pdfIn PDF document text
    • https://healthmatters.me/userfiles/file/winebozudujup.pdfIn PDF document text
    • http://togul.org/sites/default/files/file/11372712806.pdfIn PDF document text
    • https://hotelgaric.com/upload/datoteke/pajurazalaxakavatafud.pdfIn PDF document text
    • http://kreativitaet-stadlhofer.at/global/images/userfiles/file/65515438028.pdfIn PDF document text
    • http://barrospizzadb.com/uploads/files/90507208017.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/fubumorefosir.pdfIn PDF document text
    • https://okinawa4d.com/contents/files/naropuxupefugedabimimi.pdfIn PDF document text
    • http://maketmaster.ru/admin/ckfinder/userfiles/files/linavi.pdfIn PDF document text
    • http://laser-piskovani.cz/democms/userfiles/file/9158098972.pdfIn PDF document text
    • http://sntaviator.ru/ckfinder/userfiles/files/88024382291.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_off0000b3c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3C9 18184 bytes
SHA-256: 3d3b3016a430b97ac397c21669154e45483a6a695e94bb2a143bacba98804e76
font_01_sfnt_off0000e24e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE24E 10780 bytes
SHA-256: 08d1248088420916293a575948fe2ee83b79e683eccd143fcdbfec0898f78f0f
font_02_sfnt_off0000fad3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1