Malicious PDF — malware analysis report

Static analysis result for SHA-256 a76fe440fca41c20…

MALICIOUS

PDF

79.2 KB Created: 2021-09-20 06:36:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0e39fb9e021caff2a0cc4b9b1d4cba7a SHA-1: a4c3b89605e94d4adcc13da83cf3d1bffbbda8d6 SHA-256: a76fe440fca41c201f74be00ccee4784f65e160aa9b5d472074422e29a3f98cb
156 Risk Score

Malware Insights

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

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. The presence of numerous unknown URLs suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://thietkeweblongan.com/upload/files/4951831470.pdf
    • https://xn--22ck6bdp5cach0mc23a.com/ckfinder/userfiles/files/77552781876.pdf
    • http://studio-orlandini.com/userfiles/files/11293205531.pdf
    • http://senseoftourism.dk/userfiles/file/pinekudajotabusinavuzak.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef885a6635---80270746412.pdf
    • http://arcdesantmarti.com/biocop/Images/images-editor/file/65107401523.pdf
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/5b5a172b51eea2ce2ee605a5ff65620d/figelikisimorikavovuboweg.pdf
    • http://gardatrans.com/content/Files/43761947986.pdf
    • https://abss.pt/userfiles/file/busunepudox.pdf
    • http://khiensa.com/UserFiles/File/1497144867.pdf
    • https://brawlcall.com/ckfinder/userfiles/files/likaderef.pdf
    • http://globomax.eu/userfiles/file/besuxejujaluxipejuvosefi.pdf
    • http://cheapneasytrafficschool.com/CheapNEasyTrafficSchool/pa/trainstation/uploads/image/file/97475564185.pdf
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614634a7e8798---30618579727.pdf
    • http://colegiosantarosa.com/uploads/imagem/file/15951769085.pdf
    • https://newsru.md/upload/userfiles/files/tevejunopel.pdf
    • http://goodlack.cz/userfiles/file/42051921285.pdf
    • http://www.icareonline.net.au/ckfinder/icare/files/47496478503.pdf
    • https://bawauang.com/contents/files/nezik.pdf
    • http://whygzy.com/Media/Uploads/files/72091880446.pdf
    • http://patp1ryb.ru/media/file/takozitunubojubaxir.pdf
    • https://accuratesearch.com/userfiles/file/78037479556.pdf
    • http://stellarp.com/userfiles/files/44762397932.pdf
    • http://inbiosa.eu/static/cfiles/files/lozeg.pdf
    • http://kcde.kr/userfiles/file/lugixup.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=cambridge+dictionary+app+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cfee.bin
fb2ce5d36549593b488ce5a63ee586961833f6f1b5fc00268ce4c6c85d1c672a
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFEE 11020 bytes
font_01_sfnt_off0000e922.bin
15c7dc49d99d2813372f08445fdc63bfb2b7759daa8f09429fd33bae227bf17c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE922 17776 bytes
font_02_sfnt_off0001176b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1176B 16792 bytes